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 alloyRated Voltage: 48VMatch Motor: 500W motorUnder-Voltage Protection: 42±0.5VCurrent-Limiting: 27±1ASuitable for: electric bicycles and scooterSize: Approx. 83 * 65 * 37 mm / 3.26 * 2.55 * 1.45 inch Weight: Approx. 189 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 yellow&blue motor cord, the blue for positive electrode, the yellow for negative electrode. Make sure that power cord is placed rightly to prevent damage.