Smart Dual USB Car Charger Intelligently identifies your device to safely charge two devices at full speed simultaneously. Fits perfectly in the auto vehicle cigarette lighter USB charger socket. Protects devices from overheating, over-current, overcharging, and short circuits. Charging automatically stops when the battery is full. These chargers feature a built-in IC chip and safety fuse, with dual ports for independent charging of two USB-compatible devices. One port delivers a fast 2.1 amps max output, and the other provides 1 amp per port. Compatible with all USB charging cables for mobile devices, smartphones, tablets, and more.