Seiko Mod Guide

Deep technical analysis of Grand Seiko's 9S85 Hi-Beat movement—36,000 vph precision, 55-hour power reserve, and mechanical excellence. Complete comparison vs 9S65 and Swiss alternatives.

Is the Seiko NH34 GMT movement worth buying? Complete review covering NH34 reliability, accuracy expectations, strengths and weaknesses, how it compares to alternatives like Miyota 9075 and ETA 2893, and whether NH34 delivers good value for GMT watches.

What's the difference between Seiko NH35 and NH34 movements? Complete comparison covering technical specs, GMT functionality, price differences, accuracy, power reserve, which movement suits your needs, and whether GMT complication justifies NH34's premium.

Complete Seiko NH70/NH70A skeleton movement guide. Learn NH70 specifications, whether NH70 has date function, NH70 vs NH72 vs NH35 comparison, skeleton movement pros and cons, and whether NH70A delivers good quality for skeleton watches.

Complete Seiko 4R35 vs 4R36 comparison: Learn the key difference (date vs day/date), identical specs (21,600 bph, 41hr reserve, 23/24 jewels), shared features (hacking, hand-winding), which Seiko watches use them, reliability, pricing. Expert guide.

Complete guide to Seiko's 4R36 day-date automatic movement. Learn how 4R36 differs from 4R35, technical specifications, day complication functionality, where it appears in Seiko collections, accuracy expectations, and whether day-date feature justifies choosing 4R36.

The Seiko SKX007 houses the legendary Caliber 7S26-0020 automatic movement—a 21-jewel workhorse featuring 41-hour power reserve, 21,600 bph beat rate, and Seiko's Magic Lever bi-directional winding.

Discover the Seiko 4R35 automatic movement—Seiko's workhorse caliber powering Presage, Prospex, and 5 Sports collections. Complete guide covering specs, 4R35 vs NH35 differences, reliability, and best watches using this proven movement.

Complete guide to Grand Seiko's three movement technologies. Learn about 9S mechanical movements (Hi-Beat 36,000 vph), 9R Spring Drive hybrid calibers, 9F quartz accuracy, what makes Grand Seiko movements exceptional, and how they compare to Swiss alternatives.