The CR1220 is a high quality 3V Lithium coin cell battery. It is 12mm in diameter and 2mm thick. Specification Battery Technology: Lithium (Single Use) Capacity Range: 220.0mAh - 240.0mAh Current: 0.0002A Diameter: 12mm Height: 2mm Voltage: 3.00V Weight: 1g Usually used for: -Battery Mainboard PC -Battery Clock / Toy -Battery Calculator -Battery Tomsis etc.