Vintage SEIKO Ersatzteil – Clutch Cap / Copribascula (1 Stück) (Ref. 386180) - NOS GMT tight lugs or certain “sport”

tight lugs or certain “sport” and diver watches

Revision: June 2025

a hacking seconds function

Crafted from durable deerskin on the outside and cowhide on the inside

back slightly scratched (see photos)

Vintage SEIKO Ersatzteil – Clutch Cap / Copribascula (1 Stück) (Ref. 386180) - NOS GMT tight lugs or certain “sport”Rare NOS component ( Ura osae) for mechanical Seiko watch movements This original SEIKO spare part, reference 386180, is a historical component from the mechanical era (Universe series). It is the so called clutch cap copribascula (Japanese : ) a small but functionally important retaining plate within the clutch winding mechanism. Due to decades of individual storage in sealed bags, this is genuine NOS material from the early to mid Seiko mechanical