SR921SW silver oxide (SR) and alkaline batteries (LR) are commonly used in watches, clocks, timers, calculators, laser pointers, toys, and LED "blinkies". Batteries that meet the IEC 60086-3 standards for watch batteries carry a "W" suffix. The functional differences between silver oxide and alkaline are:
SR921 batteries can be used to replace the following: SR920SW, SR69, SB-BN, 280-51, V370, 620, GP370, S921E, 370, SG6, D370, 370X, 370A. 370/371, SR920PW, E370. All have dimensions of 9.5 mm diameter 2.05 mm height, and a capacity of 38 mAh.