Pocket Watch Battery: Types, Replacement Guide, and Tips Tick Tock Time Murata 379 SR521 SR521SW Watch Battery Made in Japan Button Cell THE MOST POPULAR WATCH BATTERIES Jewelry Secrets Micro Batteries Murata Manufacturing Co., Ltd. ETA Movements, Rolex Parts, Watch Batteries Star Time Supply. GENERAL SPECIFICATIONSProduct: Watch Battery Only Battery Cell Composition: Silver Oxide Recommended Uses for Product: Watch Battery Count: 1 Cell Model Compatibility: Fit COL RET BC Operating Temperature Range: 40 Degrees Celsius to +85 Degrees Celsius Shelf Life: 5 years Leakage Resistance: Anti Leak Design Movement Compatibility: Quartz Japanese Movement Water Resistance Compatibility: Suitable for 50m Water Resistant Watches Mercury Free: Environmentally Friendly (0% Hg) High Low Temperature Tolerance: Extended Performance in Extreme Climates SKU: COL RET BC_K0067196