Movement type: Japanese NH35 automatic mechanical movement Movement features: 3 hands/calendar, frequency 21,600 times per hour (3Hz), stop-second device, two-way automatic winding, 24 stone, 41 hours of energy storage. Case material: 316L stainless steel Back cover type: one-piece case, no back cover! Case diameter: 44mm (without crown) Case length: 50.7mm (total length from top to bottom) Case thickness: 17.2mm (including table mirror and bottom cover) Case ear position: 20mm (the place where the case and the strap are connected) Watch length: 260mm (total length of the watch/circumference) Strap material: 316L stainless steel Watch mirror material: anti-dazzling blue film, double bu, synthetic sapphire Crown type: screw-in Bezel material: ceramic Bezel features: 60 tooth ring unidirectional rotation Waterproof level: 300 meters waterproof/diving [can wash hands, swim, dive, meet all daily waterproof use]