5.Warm tips: please do not use it in places with low ignition point, and do not overload the charger. Always check the indicator status. When the USB port is overloaded, it will flash. Please unplug some connected devices to restore the USB port. 4.Portable design: This palm-sized USB hub charger is 3.5 x 3.42 x 1.26 inches, small and portable. Excellent travel accessories for mobile phones and many other devices. 3.All-round safety protection: WANLONGXIN USB charging station has short circuit/overcurrent/overvoltage/overheating protection, which can protect your precious equipment in all directions. This 4-port black USB hub charger is very suitable for home office charging, as well as necessities such as motorhomes, dormitories, travel hotels, etc. 2.Fast charging 3.0 ports: 5V/3.4A, 9V/2A, 12V/1.5A. Fast charging 3.0 interface is 4 times faster than ordinary USB interface. 1.Charging 4 device: 3 * 5V/0-2.4A USB port, 1 * QC 3.0 USB port, maximum total output is 40W. It will automatically detect your device and provide it with the best current. You can charge your mobile phone, Bluetooth headset and digital camera at the same time.