The LIR1254 (often marketed also as CP1254) is a button-type lithium-ion rechargeable battery, specifically designed for small electronic devices requiring a compact and rechargeable power source. It is commonly used to replace batteries in Bluetooth headphones and wireless earphones (such as some Sony, Beats or Jabra models), small sensors and smart devices. Main technical specifications Quantity: 4 pieces Model/Code: LIR1254 Battery Type: Lithium Ions (Li-Ion) Nominal Voltage: 3,7 V Capacity: 50 mAh - 65 mAh Shape Factor (Dimensions): button (Coin Cell) Diameter: 12 mm Height/Thickness: 5,4 mm Rechargeable: Yes Main Use: Wireless earphones (Bluetooth headphones), small electronic devices