Smartlet One
Smartlet One
One concept. Three different personalities
Wear a smartwatch with your Longines HydroConquest | Smartlet
Model compatibility
Wear a smartwatch
with your Longines HydroConquest
The HydroConquest is Longines at its most direct. Swiss manufacture movement, 300m water resistance, ceramic bezel, and a price that remains justifiable. The L888 calibre — developed in-house at Saint-Imier — runs at 25,200 vibrations per hour with 64 hours of power reserve. The 41mm in ceramic black or blue bezel has become one of the most recommended entry-level Swiss dive watches on the market. The recommendation holds because the watch delivers. Smartlet completes it.
Case39mm / 41mm / 43mm
Lug width18mm / 19mm / 21mm / 22mm
MovementCal. L888 / L897
Water resistance300m
Introduced1960
Smartlet compatibleYes
References
Covered references
| Reference | Smartlet | Lug width | Case | Case material | Dial |
|---|---|---|---|---|---|
| L3.780.4.56.6 | Compatible | 18mm | 39mm / 41mm / 43mm | Steel | Black |
| L3.780.4.96.6 | Compatible | 18mm | 39mm / 41mm / 43mm | Steel | Blue |
| L3.780.4.06.6 | Compatible | 18mm | 39mm / 41mm / 43mm | Steel | Green |
| L3.742.4.56.6 | Compatible | 19mm | 39mm / 41mm / 43mm | Steel | Black |
| L3.742.4.96.6 | Compatible | 19mm | 39mm / 41mm / 43mm | Steel | Blue |
| L3.781.4.56.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Stainless Steel | Black |
| L3.781.4.96.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel | Blue |
| L3.781.3.56.7 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel/Gold | Black |
| L3.781.3.96.7 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel/Gold | Blue |
| L3.781.4.06.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel | Green |
| L3.781.4.76.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel | Grey |
| L3.782.4.56.6 | Compatible | 22mm | 39mm / 41mm / 43mm | Steel | Black |
| L3.782.4.96.6 | Compatible | 22mm | 39mm / 41mm / 43mm | Steel | Blue |
| L3.742.4.56.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Stainless Steel | Black |
| L3.742.4.96.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Stainless Steel | Blue |
| L3.781.4.06.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Stainless Steel | Green |
| L3.781.4.56.9 | Compatible | 21mm | 39mm / 41mm / 43mm | Ceramic/Steel | Black |
| L3.781.4.96.9 | Compatible | 21mm | 39mm / 41mm / 43mm | Ceramic/Steel | Blue |
| L3.784.4.56.9 | Compatible | 22mm | 39mm / 41mm / 43mm | Ceramic | Black |
| L3.784.4.96.6 | Compatible | 22mm | 39mm / 41mm / 43mm | Ceramic | Blue |
| L3.784.4.06.9 | Compatible | 22mm | 39mm / 41mm / 43mm | Ceramic | Green |
| L3.784.4.76.9 | Compatible | 22mm | 39mm / 41mm / 43mm | Ceramic | Grey |
| L3.790.4.06.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel | Green |
| L3.790.4.56.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel | Black |
| L3.790.4.96.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel | Blue |
| L3.790.4.96.9 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel | Blue |
| L3.790.3.06.7 | Compatible | 21mm | 39mm / 41mm / 43mm | Steel/Gold | Green |
| L3.782.4.76.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Titanium | Grey |
| L3.781.4.99.6 | Compatible | 21mm | 39mm / 41mm / 43mm | Stainless Steel | Blue/Red |
Smartlet compatibility
The Longines HydroConquest spans 18mm to 22mm lug widths — 18mm on 32mm ladies references, 19mm on 36mm, 21mm on the standard 39mm and 41mm, and 22mm on the 43mm full ceramic. All natively supported by Smartlet.
Compatible smartwatches
Smartwatches to pair with your Longines HydroConquest
All smartwatches below can be worn simultaneously with your Longines HydroConquest via Smartlet One.
Apple Watch
View pairing guide →
Samsung Galaxy Watch
View pairing guide →
Garmin Fenix
View pairing guide →
Garmin Forerunner
View pairing guide →
Garmin Venu
View pairing guide →
Google Pixel Watch
View pairing guide →
Withings ScanWatch
View pairing guide →
Polar Vantage
View pairing guide →
Fitbit Charge
View pairing guide →
Huawei Watch GT
View pairing guide →
Coros
View pairing guide →
Suunto
View pairing guide →
Whoop
View pairing guide →
Same brand
Other Longines models
All Longines models below are also compatible with Smartlet One.
You may also like
Similar models from other brands
Watch lovers who own a Longines HydroConquest also pair Smartlet with these models.
Questions
Frequently asked
Does Smartlet work with the Longines HydroConquest?
Yes. The HydroConquest uses 18mm to 22mm lugs depending on case size — all natively supported by Smartlet. No adapter required.
Which HydroConquest references are compatible?
All — 39mm and 41mm at 21mm, 43mm ceramic at 22mm, 36mm at 19mm, and 32mm ladies at 18mm. The full range is within Smartlet's native range.
Does Smartlet affect HydroConquest water resistance?
No. Smartlet uses the spring-bar slots only. The 300m crown seals and case back are not affected.
Where can I buy Smartlet One for the Longines HydroConquest?
Smartlet One is available at smartlet.io in Classic, Shadow, and Titanium. All finishes are compatible with HydroConquest references from 18mm to 22mm.
