Wear a smartwatch with your Seiko Prospex | Smartlet

Yes. The Seiko Prospex SPB143 uses a 20mm / 21mm / 22mm lug width and is fully compatible with Smartlet. Smartlet replaces the standard strap via the spring-bar system and positions your smartwatch on the same wrist. The Seiko Prospex SPB143 requires no modification, no drilling, and no adhesive. The setup is fully reversible in seconds and your Seiko can be worn independently at any time by reinstalling its original strap.

No. Smartlet makes no contact with the Seiko Prospex SPB143 case, bezel, or crystal. It replaces the strap only, using the existing spring-bar slots. The module is manufactured in 316L stainless steel or titanium with polished and brushed finishing, and all contact points are non-abrasive. Your Seiko Prospex SPB143 is protected throughout. The system is fully reversible and leaves no trace.

Smartlet is compatible with Apple Watch (all series), Samsung Galaxy Watch (4, 5, 6, 7), Garmin Fenix (6, 7, 8), Garmin Forerunner, Garmin Venu, Google Pixel Watch, Polar Vantage, Fitbit Charge, Huawei Watch GT, Withings ScanWatch, Coros, Suunto, and Whoop. The Seiko Prospex SPB143 with its 20mm / 21mm / 22mm lug width is compatible with the full Smartlet range. All smartwatch sensors remain operational when worn via Smartlet.

Smartlet is available directly at smartlet.io in three finishes: Classic (316L stainless steel), Shadow (PVD black-coated 316L), and Titanium. All three finishes are compatible with the Seiko Prospex SPB143 and work with its 20mm / 21mm / 22mm lug width. Orders ship internationally from Europe. No additional accessory is required for standard lug widths between 18mm and 24mm.