Seiko Mod Guide

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.

This complete technical guide covers the critical difference between true GMT and caller GMT complications (which hour hand adjusts independently and why it matters)

This technical guide covers complete 9SA5 specifications, Dual Impulse Escapement operation (30% more efficient than Swiss lever), MEMS manufacturing precision, detailed comparison versus 9S85 predecessor

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 Bruce Wayne Seiko guide: Learn what this GMT mod is, why it's named after Batman's alter ego, key specs (NH34 movement, 40mm, black/grey bezel), vs Batman mod differences, pricing ($300-600), where to buy. Expert breakdown.

Discover the most popular Seiko watches from $200 to $1000+. Complete guide to Seiko 5 Sports, Prospex dive watches, Presage dress models, and premium SKX mods for 2025.