2pcs 3.7V 450mAh Battery for Udi U941 U941A U941 U943 RC quadcopter drone spare parts Package included: 2pcs batteries For Udi U27 U941 U941A U841 U843 and U842 transmitter 3.7V 450mAh Battery,,Official battery from udi Over charge protection, Short circuit protection Rechargeable up to hundreds of times