Citizen Tsuyosa 60 40mm Automatic Watch #NK0023-57L

Model Reference: NK0023-57L

Overview
The Citizen Tsuyosa NK0023-57L is a sophisticated mechanical timepiece that belongs to the Small Seconds sub-series of the Tsuyosa collection. This model is a celebration of classic watchmaking aesthetics, featuring a 41mm silver-tone stainless steel case paired with a deep midnight blue sunray dial. Unlike the standard Tsuyosa models, this version utilizes traditional lugs and a box-shaped crystal, giving it a more formal "Neo-Vintage" character. It is designed for those who appreciate mechanical complexity, offering an upgraded power reserve and a highly polished finish that functions perfectly as a dress-casual daily driver.

Technical Specifications

Case Size: 41mm (Traditional round profile with high-polished finishes)

Case Material: Silver-Tone Stainless Steel

Movement: Caliber 8310 Mechanical (Automatic, self-winding movement with a 60-hour power reserve and hacking/stop-seconds functionality)

Crystal Type: Box-Shaped Mineral Crystal (Double-domed to provide a vintage optical distortion at the edges and a unique side profile)

Water Resistance: 50 Meters (5 ATM / 165 feet) — Suitable for daily wear, splashes, and rain

Dial: Deep blue sunray dial with silver-tone "dagger" indices and sharp "Dauphine" hands

Bezel: Fixed, polished silver-tone stainless steel

Strap: Silver-tone stainless steel link bracelet with a fold-over clasp

Special Features

Extended 60-Hour Power Reserve: Driven by the Caliber 8310, this watch offers a significant autonomy of 2.5 days, allowing it to continue running accurately even if left off the wrist over a weekend.

Box-Style Crystal: The crystal sits prominently above the bezel, adding a sense of physical depth to the dial and capturing light in a way that emphasizes the sunray finish.

Exhibition Case Back: A transparent window on the case back provides a clear view of the 21-jewel automatic movement and its oscillating rotor.

Precision Time Setting: Includes a "hacking" feature, which stops the second hand when the crown is pulled out, allowing for synchronization with a reference clock.