Features The speed controller is made with high quality printed circuit board which ensures a longer service life It supports locked rotor protection by limiting the large current (maximum 30A) instead of cutting off the power This simple and easy to use DC motor speed controller has stable performance. If you use a storage battery as a power source, the low voltage protection function (10V) will prevent excessive discharge. Soft start function would protect the speed controller and motor from damage caused by large instantaneous current This motor speed controller uses screw terminals for convenient and fast wiring Description: This is a simple and easy to use DC motor speed controller, small in size, elegant appearance and stable performance. It is made with high quality PCB which ensures a longer service life. It supports soft start, locked rotor protection, low voltage protection. Features: Input voltage: DC10V-55V Output voltage: Linear with load Output Current: 0A-40A Limit current: 30A Speed range: 0% to 100% Control method: potentiometer (linear, 270°) Control frequency: 15KHz Wiring Type: Screw Terminal Rotary knob: 10K (with switch) Size: 80 x 56 x 28 mm/3.15 x 2.2 x 1.1 inches. Package includes: 1 x Speed Controller Package List