Mainly used for 12V fan, blower, ceiling fan, exhaust fan speed regulation, and charging mobile phones and tablets The input line is 18cm long, the output line is 115cm long, and the 5.5x2.1mm port with positive electrode in middle and negatived electrode outside Multifunctional 40W USB+20W Type C charging adapter with voltmeter, compatibility with multiple devices, supporting up to 12V3A Equipped with speed control switching button, adjustable from 0-50 gears, to use, blue LED display, and screen display of input voltages 5.5x2.1mm female input can link with power adapter, 5.5x2.1mm male output can connection with fan and more