BATTERY-CR1220

a CR1220 Lithium Coin Cell Battery. These are small but powerful batteries commonly used in compact electronics.
​Here is a breakdown of what those specifications mean and how the battery works:
​What the "CR1220" Label Means
​The name is actually a code for the battery's physical dimensions and chemistry:
​C: Lithium chemistry (Manganese Dioxide Lithium).
​R: Round shape.
​12: The diameter in millimeters (12 mm).
​20: The height or thickness in tenths of millimeters (2.0 mm