Wear a smartwatch with your Longines

Wear a smartwatch with your Longines

Smartlet One is compatible with all Longines HydroConquest, Spirit, and Record references using 20mm to 22mm lug widths, natively supported with no adapter. Installation uses the standard spring-bar system - no modification to the watch, fully reversible in seconds.
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Longines compatibility

Wear a smartwatch with your Longines

In short Smartlet One is compatible with all Longines HydroConquest, Spirit, and Record references using 20mm to 22mm lug widths, natively supported with no adapter. Installation uses the standard spring-bar system - no modification to the watch, fully reversible in seconds.

Longines has been making watches continuously since 1832, longer than any other Swiss brand with the same name. The HydroConquest is a serious dive watch at accessible pricing. The Spirit revisits the aviation instrument watch with COSC-certified movements. Longines occupies a precise position in Swiss watchmaking - genuine quality without the prestige premium. Smartlet One fits without adapters and removes without tools.

Wear yours How it works
The problem
Choosing between health data and horological heritage every morning.
The solution
Smartlet One replaces your Longines's strap via the standard spring-bar system and positions your smartwatch on the same wrist. Both watches run simultaneously, with no modification to the watch and full reversibility in seconds.
Brand
Longines
Lug widths
18.0mm / 19.0mm / 20.0mm / 21.0mm / 22.0mm / 23.0mm
Iconic models
1covered
Compatibility
Full range

Choose your edition

One mechanism. Three personalities.

Every Smartlet One includes the dedicated adapter for your wearable. Pick the finish that matches your style.

Smartlet One - Shadow - Smartlet

For the explorer

Smartlet One - Shadow

€399,00

4.9 (17)

Stealth. Switch in seconds, leave no trace.

  • Material SS316L steel, black PVD
  • Weight ~100g
  • Compatible with Rolex, Omega, Seiko + 100 more
Buy now
Compatibility

Longines models supported

Longines HydroConquest
18mm / 19mm / 21mm / 22mm

Other Longines references

32 model families. Expand any group to see variants, references, and specifications.

Admiral
19mm / 20mm6 refs+
ReferenceMaterialDialLugSmartlet
Admiral-1966Stainless SteelSilver19mmCompatible
Adm5S-1968Stainless SteelBlack19mmCompatible
Admiral-2003Stainless SteelBlack20mmCompatible
Admiral-80Q-1982Stainless SteelBlue19mmCompatible
Admiral-80B-1985Stainless SteelBlack19mmCompatible
L3.614.4.76.6Stainless SteelGrey20mmCompatible
Automatic
18mm1 refs+
ReferenceMaterialDialLugSmartlet
Cal340-1960Stainless SteelSilver18mmCompatible
BigEye
20mm1 refs+
ReferenceMaterialDialLugSmartlet
L2.816.4.53.2Stainless SteelBlack20mmCompatible
Chronograph
18mm / 19mm16 refs+
ReferenceMaterialDialLugSmartlet
13ZN-1-1936Stainless SteelSilver18mmCompatible
13ZN-2-1938Stainless SteelBlack18mmCompatible
13ZN-S-1939Stainless SteelSilver Sector18mmCompatible
13ZN-1939Stainless SteelSilver18mmCompatible
13ZN-SN-1940Stainless SteelWhite Snail18mmCompatible
13ZN-FLY-1940Stainless SteelWhite19mmCompatible
13ZN-MIL-1941Stainless SteelBlack Military19mmCompatible
13ZN-WP-1941Stainless SteelSilver19mmCompatible
13ZN-RG-194218K Rose GoldCream18mmCompatible
30CH-1951Stainless SteelWhite18mmCompatible
30CH-1952Stainless SteelSilver19mmCompatible
30CH-BLK-1953Stainless SteelBlack19mmCompatible
30CH-LAN-1955Stainless SteelSilver19mmCompatible
30CH-RG-1956Rose GoldSilver19mmCompatible
30CH-1957Stainless SteelSilver19mmCompatible
30CH-AM-1958Stainless SteelSilver19mmCompatible
Conquest
18mm / 19mm / 20mm / 21mm / 22mm18 refs+
ReferenceMaterialDialLugSmartlet
CQ-1988-100MStainless SteelSilver20mmCompatible
L3.430.4.09.6SteelGreen20mmCompatible
L3.430.4.52.6SteelBlack20mmCompatible
L3.430.4.97.6SteelBlue20mmCompatible
L3.700.4.56.6Stainless SteelBlack22mmCompatible
L3.778.4.56.6Stainless SteelBlack21mmCompatible
L3.778.4.96.6Stainless SteelBlue21mmCompatible
L3.835.4.56.2SteelBlack22mmCompatible
L3.835.4.92.2SteelBlue22mmCompatible
Cal19AS-1954Stainless SteelSilver18mmCompatible
JDM-CQ-1998Stainless SteelWhite19mmCompatible
Cal290-1956Stainless SteelSilver18mmCompatible
L3.726.4.56.6SteelBlack20mmCompatible
L3.726.4.96.6SteelBlue20mmCompatible
L3.727.4.56.6SteelBlack21mmCompatible
L3.727.4.76.6SteelSilver21mmCompatible
L3.716.4.56.6Stainless SteelBlack21mmCompatible
L3.716.4.96.6Stainless SteelBlue21mmCompatible
DolceVita
18mm / 19mm / 20mm4 refs+
ReferenceMaterialDialLugSmartlet
L5.657.4.51.2Stainless SteelBlack20mmCompatible
L5.155.4.16.6Stainless SteelWhite Roman18mmCompatible
L5.655.4.71.3Stainless SteelSilver19mmCompatible
L5.655.4.71.6Stainless SteelSilver Small Seconds19mmCompatible
Dress
18mm1 refs+
ReferenceMaterialDialLugSmartlet
JDM-DR-1990Stainless SteelWhite18mmCompatible
Elegant
18mm / 20mm2 refs+
ReferenceMaterialDialLugSmartlet
L4.310.4.12.6Stainless SteelSilver18mmCompatible
L4.910.4.92.6Stainless SteelBlue20mmCompatible
Evidenza
18mm / 20mm / 21mm5 refs+
ReferenceMaterialDialLugSmartlet
L2.642.4.73.4Stainless SteelSilver18mmCompatible
L2.642.4.51.4Stainless SteelBlack18mmCompatible
L2.643.4.51.0Stainless SteelBlack21mmCompatible
L2.642.4.73.3Stainless SteelSilver Guilloché20mmCompatible
L2.643.4.78.6Stainless SteelSilver21mmCompatible
Flagship
18mm / 19mm11 refs+
ReferenceMaterialDialLugSmartlet
Cal12.68Z-1958Stainless SteelSilver18mmCompatible
L4.746.4.72.4Stainless SteelSilver19mmCompatible
L4.974.4.12.6Stainless SteelWhite19mmCompatible
Cal340-1958Stainless SteelSilver18mmCompatible
L4.795.4.78.2Stainless SteelCream19mmCompatible
L4.795.4.52.0SteelBlack19mmCompatible
L4.795.4.78.2SteelSilver19mmCompatible
JDM-FS-1997Steel/Gold CapChampagne18mmCompatible
JDM-FS-2003Stainless SteelSilver18mmCompatible
JDM-FS-2004Stainless SteelBlack18mmCompatible
Cal340-Linen-1962Stainless SteelSilver Linen18mmCompatible
Grand
19mm1 refs+
ReferenceMaterialDialLugSmartlet
9712-1990Stainless SteelSilver19mmCompatible
Greenlander
20mm1 refs+
ReferenceMaterialDialLugSmartlet
Greenlander-LONG-1945Stainless SteelBlack20mmCompatible
Heritage
19mm / 20mm / 22mm / 23mm30 refs+
ReferenceMaterialDialLugSmartlet
L2.838.4.53.2Stainless SteelBlack22mmCompatible
L2.794.4.53.0SteelBlack22mmCompatible
L2.813.4.66.0Stainless SteelSalmon20mmCompatible
L2.816.1.93.2BronzeGreen20mmCompatible
L2.816.4.53.2SteelBlack20mmCompatible
L2.816.1.93.2TitaniumBlue20mmCompatible
L2.828.4.73.2Stainless SteelSilver Sector19mmCompatible
L2.828.4.53.2SteelBlack Sector19mmCompatible
L2.828.4.73.2SteelSilver Sector19mmCompatible
L2.828.4.53.2Stainless SteelBlack Sector19mmCompatible
L2.750.4.56.2Stainless SteelBlack20mmCompatible
L2.744.4.56.2Stainless SteelBlack22mmCompatible
L2.808.4.52.6Stainless SteelBlack/Red22mmCompatible
L2.841.4.56.4Stainless SteelBlack22mmCompatible
L3.674.4.50.0SteelBlack22mmCompatible
L3.774.4.50.0SteelBlack22mmCompatible
L3.774.4.90.2SteelBlue22mmCompatible
L3.774.1.50.2BronzeBlack22mmCompatible
Lind-LE-1996Stainless SteelWhite20mmCompatible
L2.713.4.13.0Stainless SteelWhite20mmCompatible
L2.833.4.93.2Stainless SteelBlue19mmCompatible
L2.826.4.53.2Stainless SteelBlack20mmCompatible
L2.834.4.72.2Stainless SteelSilver19mmCompatible
L2.822.4.56.9SteelBlack22mmCompatible
L2.822.4.93.2SteelBrown22mmCompatible
L2.330.4.93.0Stainless SteelBlack/White19mmCompatible
L2.330.4.93.0SteelTwo-Tone19mmCompatible
L2.812.4.23.2Stainless SteelWhite Offset20mmCompatible
L2.713.8.11.0SteelWhite23mmCompatible
L2.607.4.23.2Stainless SteelWhite20mmCompatible
Legend
18mm / 22mm6 refs+
ReferenceMaterialDialLugSmartlet
LLD-LE-2009Stainless SteelBurgundy22mmCompatible
L3.674.4.50.0Stainless SteelBlack22mmCompatible
L3.774.4.50.0Stainless SteelBlack Date22mmCompatible
L3.374.4.50.2SteelWhite18mmCompatible
L3.374.4.56.2SteelBlack18mmCompatible
L3.374.4.90.2SteelBlue18mmCompatible
Lindbergh
18mm / 22mm2 refs+
ReferenceMaterialDialLugSmartlet
L2.601.4.11.0Stainless SteelSilver18mmCompatible
Lind-LE-YG-200218K Yellow GoldWhite22mmCompatible
Longines
18mm / 19mm / 20mm / 22mm15 refs+
ReferenceMaterialDialLugSmartlet
L1954-ANNIV-2004Stainless SteelSilver19mmCompatible
30L-1960Stainless SteelSilver18mmCompatible
JDM-ADM-1994Stainless SteelSilver18mmCompatible
A7-LE-2002Stainless SteelWhite Offset20mmCompatible
L3.155.4.52.JStainless SteelBlack20mmCompatible
L2.919.4.71.2Stainless SteelGrey20mmCompatible
JDM-EL-2003Stainless SteelSilver Sunburst19mmCompatible
L1.611.6.75.2Gold CapChampagne18mmCompatible
Lind-HourAngle-1931Stainless SteelWhite22mmCompatible
JDM-Prom-1995Stainless SteelWhite19mmCompatible
MN-LE-2005Stainless SteelSilver19mmCompatible
JUB-1905-2005Stainless SteelSilver20mmCompatible
LSC-1994Stainless SteelWhite20mmCompatible
L3.615.4.76.6Stainless SteelGrey20mmCompatible
Lind-Weems-1937Stainless SteelSilver20mmCompatible
Master
18mm / 19mm / 20mm / 21mm / 22mm14 refs+
ReferenceMaterialDialLugSmartlet
L2.910.4.78.3Stainless SteelSilver20mmCompatible
L2.629.4.51.6Stainless SteelBlack22mmCompatible
L2.673.4.78.3Stainless SteelSilver20mmCompatible
L2.629.4.78.3SteelSilver20mmCompatible
L2.257.4.75.6SteelBlue18mmCompatible
L2.257.4.78.6SteelSilver18mmCompatible
L2.628.4.75.6SteelBlue19mmCompatible
L2.628.4.78.6SteelSilver19mmCompatible
L2.893.4.71.6SteelSilver21mmCompatible
L2.893.4.79.2SteelBlue21mmCompatible
L2.673.4.78.3SteelBlue20mmCompatible
L2.673.4.78.6SteelSilver20mmCompatible
L2.909.4.92.6Stainless SteelBlue21mmCompatible
L2.409.4.78.6Stainless SteelSilver20mmCompatible
Military
18mm / 20mm2 refs+
ReferenceMaterialDialLugSmartlet
HS-Longines-1942Stainless SteelBlack20mmCompatible
WWW-Longines-1945Stainless SteelBlack18mmCompatible
Presence
19mm / 20mm4 refs+
ReferenceMaterialDialLugSmartlet
L4.722.4.12.2SteelSilver19mmCompatible
L4.921.4.12.6SteelSilver20mmCompatible
L4.921.4.52.2SteelBlack20mmCompatible
JDM-PRE-2001Stainless SteelSilver19mmCompatible
Professional
20mm2 refs+
ReferenceMaterialDialLugSmartlet
L3.635.4.56.6Stainless SteelBlack20mmCompatible
L3.635.5.88.6Steel/Gold CapChampagne20mmCompatible
Présence
20mm2 refs+
ReferenceMaterialDialLugSmartlet
L4.921.4.12.6Stainless SteelWhite20mmCompatible
L4.790.4.12.7Stainless Steel/Gold CapWhite20mmCompatible
RAF
18mm1 refs+
ReferenceMaterialDialLugSmartlet
6B-Longines-1940Stainless SteelBlack18mmCompatible
Record
19mm / 20mm4 refs+
ReferenceMaterialDialLugSmartlet
L2.821.4.76.2SteelSilver19mmCompatible
L2.821.4.96.2SteelBlue19mmCompatible
L2.821.4.72.2SteelSilver20mmCompatible
L2.921.4.56.2Stainless SteelBlack20mmCompatible
Saint-Imier
18mm / 21mm2 refs+
ReferenceMaterialDialLugSmartlet
L2.752.4.52.6SteelBlack21mmCompatible
L2.563.4.78.6SteelSilver18mmCompatible
Silver
19mm1 refs+
ReferenceMaterialDialLugSmartlet
L2.834.4.72.2Stainless SteelSilver19mmCompatible
Skin
22mm1 refs+
ReferenceMaterialDialLugSmartlet
L2.822.4.56.2Stainless SteelBlack22mmCompatible
Spirit
19mm / 20mm / 21mm / 22mm21 refs+
ReferenceMaterialDialLugSmartlet
L3.810.4.53.6SteelBlack20mmCompatible
L3.810.4.73.6SteelSilver20mmCompatible
L3.810.4.93.6SteelBlue20mmCompatible
L3.811.4.53.6SteelBlack22mmCompatible
L3.811.4.93.6SteelBlue22mmCompatible
L3.810.4.53.0Stainless SteelBlack21mmCompatible
L3.811.4.93.6Stainless SteelBlue22mmCompatible
L3.820.4.53.0Stainless SteelBlack22mmCompatible
L3.821.4.53.6SteelBlack22mmCompatible
L3.821.4.93.6SteelBlue22mmCompatible
L3.810.4.03.2Stainless SteelGreen21mmCompatible
JDM-SP-1999Stainless SteelChampagne19mmCompatible
L3.810.1.73.2TitaniumGrey20mmCompatible
L3.811.1.73.2TitaniumGrey22mmCompatible
L3.810.1.53.2TitaniumAnthracite21mmCompatible
L3.812.4.93.6Stainless SteelBlue Gmt22mmCompatible
L3.812.4.06.6SteelGreen22mmCompatible
L3.812.4.63.6SteelBlack22mmCompatible
L3.812.4.93.2SteelBlue22mmCompatible
L3.802.4.23.6SteelWhite20mmCompatible
L3.802.4.93.6SteelBlue20mmCompatible
Tuxedo
20mm1 refs+
ReferenceMaterialDialLugSmartlet
TUX-LE-2008Stainless SteelBlack/White20mmCompatible
USA
21mm1 refs+
ReferenceMaterialDialLugSmartlet
L2.784.4.96.0Stainless SteelBlue21mmCompatible
Ultra-Chron
18mm / 22mm4 refs+
ReferenceMaterialDialLugSmartlet
2221042Stainless SteelBlack22mmCompatible
L2.836.4.52.6Stainless SteelBlack/Red22mmCompatible
L2.836.4.52.9Stainless SteelBlack/Red22mmCompatible
431-1969Stainless SteelSilver18mmCompatible
UltraQuartz
18mm / 19mm2 refs+
ReferenceMaterialDialLugSmartlet
Cal6512-1970Stainless SteelSilver19mmCompatible
ULTRAQ-1975Stainless SteelSilver18mmCompatible
VHP
18mm / 19mm / 20mm5 refs+
ReferenceMaterialDialLugSmartlet
VHP-CHRO-1993Stainless SteelBlack20mmCompatible
VHP-G1-1984Stainless SteelSilver18mmCompatible
VHP-G1-BLK-1985Stainless SteelBlack18mmCompatible
VHP-G2-1990Stainless SteelSilver19mmCompatible
5345-VHP-1992Steel/Gold CapChampagne19mmCompatible

Longines lug widths:

18mm19mm20mm21mm22mm23mm
Frequently paired

Smartwatches worn with Longines

The most common combinations our customers wear. Find your mechanical watch and discover the right Smartlet edition.

Apple Watch
Series 0 to Ultra 3
Whoop
5.0 / MG
Garmin Forerunner
255 to 965
Samsung Galaxy Watch
Series 4 to 7
Withings ScanWatch
Light / 2 / Nova
View all brands
27 brands covered
Also compatible

Other brands

Smartlet One covers 18mm to 24mm lug widths across the finest watch brands.

Rolex
Omega
Tag Heuer
Breitling
Tudor
IWC
Seiko
Hamilton
Grand Seiko
Bell&Ross
Blancpain
Panerai
Cartier
Jaeger Lecoultre
Zenith
Rado
Tissot
Oris
Doxa
Formex
Timex
Sinn
Porsche Design
Mido
Yema
Christopher Ward
View all
Watch brand compatibility guide

Step by step

Replace your strap
01

Replace your strap

Smartlet replaces your mechanical watch strap via the standard spring-bar system. Classic, Shadow, or Titanium. No tools required.

Connect your wearable
02

Connect your wearable

Smartlet uses a dedicated adapter or native lug pins depending on your smartwatch. The connector snaps onto the Smartlet module. Zero modification to the mechanical watch.

Wear both simultaneously
03

Wear both simultaneously

Both watches sit on the same wrist. All smartwatch sensors maintain direct skin contact and operate normally.

Questions

Frequently asked questions

  • Does Smartlet work with Longines watches?
    Yes. Longines references from 18mm to 22mm lug width are natively supported by Smartlet One.
  • Which Longines models have guides?
    The HydroConquest has a full reference table covering 29 references from 39mm to 43mm.
  • Will Smartlet affect my Longines?
    No. Smartlet attaches via the spring-bar slots. The L-EVO calibre and case seals are unaffected.
  • Which recent Longines releases work with Smartlet?
    Longines gave the HydroConquest a significant overhaul for 2026, introducing a next generation with a mesh bracelet option and a frosted blue dial. As always, any reference with standard spring bars between 18mm and 24mm lug width works with Smartlet.
  • Does Smartlet damage or modify my mechanical watch?
    No. Smartlet replaces your standard watch strap using the existing spring-bar system. It makes no permanent modification to the watch case, lugs, or dial. The process is fully reversible in seconds. Your mechanical watch is unaffected and can be worn independently at any time by reinstalling its original strap. Smartlet is engineered to watchmaker tolerances and tested with the same care that goes into the watches it pairs with.