Seiko SUS Military twins
By: reintitan : September 7th, 2019-22:30
Both from 1996. The Seiko cal. 4S15 hacks, hand-winds, and runs at 28,800 bph. Compare to the cal. 7S26 that later replaced it which does not hack nor hand-winds and runs at a slower 21,600 bph. Even today's Seiko 6S and 4R series of movements run at 21,6...