GoolRC Super Fly 4-port Fast Charger Sets with 3.7V 750mAh Lipo Battery for RC Helicopter / Quadcopter JJRC H12C DFD F181 MJX X400 High quality and durable perfermace. Portable and easy to carry. X4 charger can charge four battery once time. Safety for the using time of battery. Can be applied for many types of RC vehicle.