Battery Type: Li-ion Polymer battery Capacity: 320mAh Nominal Voltage: 3.7V Pack Dimension: 4.0 x 25.0 x 36.5mm Weight: 10g Working Temperature: Less than 60℃(140℉) Compatible Models: AKG N60 NC Headphone Cautions: 1. DO NOT ATTEMPT OPEN, DISASSEMBLE THE BATTERY. 2. DO NOT CRUSH, PUNCTURE OR DISPOSE OF IN FIRE OR WATER. 3. DO NOT EXPOSE TO ABOVE 60℃(140℉).