3.7V 650mAh Replacement Polymer Lithium Battery Part-08 Compatible with Haktoys HAK448 4 Channel 15" RC Helicopter Package contents: 1 x 3.7V 650mAh Replacement Battery Obtain longer flight time. High quality and durable. Works with Haktoys HAK448 4 Channel 15" RC Helicopter and other compatible RC hobby products Make sure to follow battery precautions. Do not overcharge or overdischarge. Please make sure to allow short break between flights in order to prevent circuit board and motor failures.