The 'Tsuyosa' Automatic, from the NJ015 series, brings ultramodern sports styling right to your wrist. Executed in a versatile 40mm footprint, the sophisticated design of the watch makes a strong impression via a gold-tone stainless steel case and a seamlessly integrated, matching bracelet. Underneath an anti-reflective sapphire crystal, the sporty timepiece makes use of a sunray green dial, with a 3 o'clock date window and contrasting gold-tone details adding to its classic aesthetic. Powered by an automatic movement and offering up to 50 meters of water resistance, the refined timepiece is a daily wearing choice ready for work, play, and everything in between. Caliber 8210. Automatic Movement Technology: Powered by the release of a wound spring, mechanical movements never require a battery. Automatic mechanical movements have an oscillating weight that winds the spring with the motion of the wearer's arm. 42 Hour Power Reserve 3 Hand with Date Case Width (mm): 40 Lug Width (mm): 9 Bracelet: Yellow Gold-Tone Stainless Steel Case Material: Yellow Gold-Tone Stainless Steel Sapphire Crystal: Superior scratch resistance and hardness Fold Over Clasp with Push Buttons Dial: Green Water Resistance: WR50/5Bar/166ft [Still Water Swimming] Citizen Eco-Drive Style #: NJ0152-51X.