Wear a Smartwatch with Your Grand Seiko | Smartlet

Smartlet One is compatible with all Grand Seiko Spring Drive, Hi-Beat, and Quartz references using 19mm to 20mm lug widths, natively supported with no adapter. Installation uses the standard spring-bar system - no modification to the watch, fully reversible in seconds.

Grand Seiko produces some of the finest dials in watchmaking. The Shinshu forest textures, the Shizukuishi snowflake patterns - each reference is finished by hand to standards that require magnification to appreciate fully. The Spring Drive movement occupies a unique mechanical position: a mainspring regulated by a tri-synchro escapement, accurate to one second per day. Wearing Grand Seiko on one wrist is already a considered decision. Smartlet One adds data to that wrist without touching the case.