After placing your order, please feel free to pay attention to us and reply in time, thank you for your cooperation! This JH5AJ6339DZMN controller, voltage 52V, maximum current 25A, size 11.45.23cm (4.4821.18 inches). (1) brake: low brake (2) power: 12 magnet steel (3) instrumentation: 2 protocol five gears gear control power and electric (4) tail lights: brake lights, running lights (5) speed limit: instrument P08 adjustable (6) speed 55km (7) USB interface. For electric bicycles, scooters, etc. The controller shell is made of high quality aluminum alloy with groove design. It has good heat dissipation and can protect the internal circuit from thermal overload. JH5AJ6339DZMN brushless motor controller has stable speed and sensitive brake and commutation control. The wires and interfaces are durable to ensure low failure rate in long-term use. 1 Brushless motor controller. Carefully study customer needs, according to the customer’s actual installation situation to provide detailed and suitable solution environment. Try our best to meet the reasonable needs of customers. Cooperate with customers in a friendly manner to meet their needs with the best quality products. Free training for customers on how to install and use the e-bikes. Perfect after-sales service to help customers solve problems in the process of using. Provide regular tracking service for customers. Please indicate your personal requirements such as color, packaging, etc. If you are not satisfied with the item when you receive it, please contact me before returning it.