Seiko NH35 (NH35A) Movement — Reference & Specifications
The Seiko NH35 (NH35A) is an automatic mechanical movement made by Seiko Instruments (SII/TMI). It hacks, hand-winds, runs at 21,600 bph on 24 jewels, and holds roughly 41 hours of reserve. Mechanically it is the unbranded twin of Seiko's 4R35, which is why it powers the Seiko 5 family and became the default 'heart' of the microbrand and mod world.