This USB drone battery cable is specifically designed to charge 3.7V lithium/nickel-metal hydride nichrome batteries, making it compatible with various models of Attop XT-1 RC Drones, RC Cars, Quadcopters, WiFi FPV Drones, and Airplanes. Input voltage: 5V Output: 3.7V Interface type:USB/DC 2.0mm Length of cable: 30cm Package includes: 4 x 3.7V USB Charger Cable