1.2V NiMH Button Battery, 40mAh discharge at the small current and apply on the machine. NiMH Button BatteryCapacity: 40mAhVoltage: 1.2VDimension: 11.6*5.4mmIt can make the battery pack as the different working voltage. It has the long cycle life and stable quality and applys widely on the measurement instrument as the power backup NiMH Button Battery battery backup 1.2V 40mAh