SM-4P Connector plug, only suitable for some kind Auto Electronic gel Water Spltter Ball Blaster or RC Car toy battery, don\'t use in other deivce, cause positive and negative polar maybe reversed with this item. 3.7V 0.5A x 2 USB charger cable, Built-in over charged protection IC circuit board,red light is solid when charging, red indictor is off ..

Do not fit other device besides HJ808 UDI008 UDI001 RC Boat. SM-4P Connector Plug, Only in RC Boat Battery which use same SM-4P plug. When put in plug convex side on above,flat side on below., first and third pin is positive, second and forth pin is negative. please make sure your battery is same. don\'t reversed. 7.4V / 2 x 3.7V 400mA USB Charger ..