How To Change A Battery In A Mk Watch at Ruth Gray blog Amazon.com: Technical Precision Replacement for 7237 : Tools & Home [A2277] OEM Replacement Battery For Watch Series 5 40mm & Series SE Seiko Pulsar 1F20 Movement. GENERAL SPECIFICATIONSProduct: Watch Battery Only Battery Cell Composition: Silver Oxide Recommended Uses for Product: Watch Battery Count: 1 Cell Model Compatibility: Fit FCK2237 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: FCK2237_K0063138