Description
The Citizen NK5010-51L (also referenced as NK501051L) is a modern, high-performance Japanese automatic timepiece from Citizen’s acclaimed Mechanical Collection. Recognized globally by watch collectors and style enthusiasts by its popular collection series nicknames—the "Tsuyosa Small Second" or "Tsuyosa 60"—this 40mm watch pairs an integrated stainless steel case with a guilloché-textured stamped blue dial, a prominent small seconds sub-dial at 6 o'clock, an upgraded in-house automatic movement with an extended power reserve, an exhibition see-through caseback, a scratch-resistant sapphire crystal, and an integrated solid stainless steel bracelet. Inspired by retro 1970s luxury sports watch design language, it bridges everyday versatility with elevated mechanical watchmaking. The defining visual highlight of this NK5010-51L reference is its captivating textured blue dial featuring a guilloché pattern that captures light from every angle. Set beneath an anti-reflective sapphire crystal, the dial features contrasting silver-tone baton hour markers and hands coated with luminous accents, an off-centered recessed small seconds sub-dial at 6 o'clock with fine guilloché detailing, and a sleek recessed crown at the 4 o'clock position to maintain an ergonomic case profile. The rich blue dial texture paired with polished stainless steel components delivers a vibrant, sporty, yet sophisticated wrist presence. Beneath its sporty exterior, the watch is driven by Citizen's upgraded in-house Caliber 8322 automatic mechanical movement with hand-winding and second-hand hacking capabilities. Operating at 21,600 vibrations per hour (3 Hz) across 21 jewels, this caliber delivers an impressive 60-hour power reserve, allowing the timepiece to keep precise time even if off the wrist over a full weekend. The case features well-balanced, contemporary sports watch dimensions, measuring 40.0mm in dial case width with an ultra-sleek profile thickness of 11.7mm and a total weight of approximately 147 grams, ensuring a comfortable, planted feel on the wrist. Superior optical clarity and dial protection are provided by a scratch-resistant anti-reflective sapphire crystal. The reverse side features an exhibition see-through caseback that showcases the operating automatic movement and rotor. Engineered for active daily wear, the solid stainless steel case achieves a certified 50-meter (5 bar / 165 ft) water resistance rating. The timepiece comes completed on an integrated stainless steel link construction with a quick-release mechanism for easy strap swapping, secured by a solid deployment clasp with push-button release.
