620mAh 2.29Wh Battery for Sennheiser HD 4.40 BT Wireless Bluetooth Headphone
Compatable with : For Sennheiser HD 4.40 BT Wireless Bluetooth Headphone. Battery Capacity : 3.7V 650mAh 2.40Wh. The Tools is free, so i can't Promise tools will be suitable for your Device. For example.