Features: 1. The controller shell is made of aluminium alloy, which can protect the inner circuit and good for heat dissipation to avoid thermal overloading. 2. This item is a brushed motor controller, it can provide steady speed and sensitive control of braking and direction changes. 3. The wires and interfaces are durable, and ensure low malfunction of long time use. 4. The interfaces have instruction labels on them for your easy installation. 5. Suitable for electric bicycles and scooter. Specification: Material: Aluminium alloy Rated Voltage: 24V Match Motor: 250W motor Speed Regulator: 1-4V Low-Voltage Protection: 20V Suitable for: electric bicycles and scooter Size: Approx. 75 * 50 * 35 mm / 2.95 * 1.96 * 1.37 inch Weight: Approx. 122 g Package List: 1 * Brushed Controller Noted : 1. Please read the labels on the interfaces of the controller, make sure that every interface is rightly connected to what it matches. 2. To the thick black&red power cord, the red is for battery positive electrode, and black for battery negative electrode. to the thick white&blue motor cord, the blue for positive electrode, the white for negative electrode. Make sure that power cord is placed rightly to prevent damage.