3pcs 3.7V 600mAh Lipo Battery for Syma X1 Quadcopter Size: 58 X 19 X 7mm. A little bit bigger than original one. Capacity: 600mAh; Upgraded battery for longer flying time. 3 pieces Compatible with Syma X1, WLtoys V929 V959 V222 and any other copters with the same volt and plug JST Plug