Wear your Garmin Forerunner with your mechanical watch | Smartlet
Wear your Garmin Forerunner
and your mechanical watch
at the same time
The Garmin Forerunner is built for runners and triathletes who take their training data seriously - VO2 max, HRV status, training readiness, multi-band GPS. Your Rolex or TAG Heuer belongs to a different register entirely. Smartlet One clips your Forerunner onto any mechanical watch strap via a 20mm adapter, so both can live on the same wrist. Forerunner 255S and 265S (41mm) use an 18mm lug width, natively supported by Smartlet. No adapter required.
How it works
Classic, Shadow, or Titanium. Match your mechanical watch case material and aesthetic. No tools required at this stage.
Attach the Smartlet adapter to your watch lugs. The spring-loaded mechanism locks in place with zero metal-to-metal case contact. Fully reversible in seconds.
Attach the Smartlet adapter to your Garmin Forerunner. It locks securely. Both watches sit on the same wrist. All sensors remain in contact with your skin.
Garmin Forerunner models supported
| Series | Smartlet compatible | Lug width | Release year | Case size |
|---|---|---|---|---|
| Forerunner 255S | Compatible | 20 mm | 2022 | 41mm |
| Forerunner 255 | Compatible | 22 mm | 2022 | 46mm |
| Forerunner 255 Music | Compatible | 22 mm | 2022 | 46mm |
| Forerunner 265S | Compatible | 20 mm | 2023 | 41mm |
| Forerunner 265 | Compatible | 22 mm | 2023 | 46mm |
| Forerunner 955 | Compatible | 22 mm | 2022 | 46mm |
| Forerunner 965 | Compatible | 22 mm | 2023 | 47mm |
Mechanical watches worn with Garmin Forerunner
Other smartwatches
Frequently asked
Can I wear a Garmin Forerunner and a mechanical watch at the same time?
Yes. Smartlet One is a modular adapter that clips onto any mechanical watch via an 18mm to 24mm adapter, allowing you to simultaneously wear your Garmin Forerunner on the same wrist. Both watches operate independently. No modification required.
Which Garmin Forerunner models are compatible with Smartlet?
Garmin Forerunner 255, 265, 955, and 965 are all compatible with Smartlet. The standard variants (46-47mm) use 22mm lugs and are natively supported. The S variants (255S, 265S at 41mm) use 18mm lugs, natively supported by Smartlet.
Will Garmin Forerunner sensors still work when attached to Smartlet?
Yes. All Garmin Forerunner sensors including Pulse Ox SpO2, optical heart rate, HRV status, and training readiness maintain full wrist contact via Smartlet. Multi-band GPS performance is hardware-based and completely unaffected.
Does Smartlet work with Garmin Forerunner 965?
Yes. The Forerunner 965 uses a 22mm lug width and is fully compatible with Smartlet. All health sensors and GPS remain operational.