Description: Specialised Lithium Battery Coin Cell Application: Memory Back Up (MBU) Laptop Computer Chemistry: Lithium Manganese Dioxide Voltage: 3V Nominal Capacity: 220mAh Brand: Master (this battery is a compatible alternative to that of the original brand) Size Coin Width: 20mm Height: 3.2mm Replacement cmos/RTC battery for IBM Thinkpad 560X, 570, A20m, A20p, A21, A21e, A21m, A21p, A22, A22e, A22m, A22p, A30, A30p, A31, A31P, T20, T21, T22, T23, T30, T43, T43P. Replaces IBM Parts FRU 02K6541, 02K6572, 12J1671, 12J1695