The TU21558ac includes built-in intellichip technology, which reads the power needs of devices to optimize charging speeds. This protects against overcharging and short-circuiting, so you can charge your smart devices with peace of mind. The tu21558ac type-c port charges up to 5v/3. 0a, the type-a port charges up to 5v/2. 4a, and the outlet has a combined total of 5. 8a charging output. With the tu21558ac, power old devices and be ready for new devices with the combination of type-c and type-a usb charging ports.