Case: Case Size 3H-9H: 30.5mm Case Size 12H-6H: 36.6mm Case Material: Stainless Steel Caseback Design: See-through Caseback Caseback Structure: Screw Caseback Glass Material: Crystal Glass Glass Material: Caseback: Crystal Glass Pair: RE-AT0205L Movement: Automatic Self-Winding: Yes Jewels: 20 Jewels Vibration: 21,600 vibrations/hour Hand Winding: Yes Movement: Mechanical Caliber Code: Cal.55C22 Made in Japan Feature: Water Resistance: 5bar (50m)