This is a 48V, 35A controller. These types of controllers are commonly (though not exclusively) used for electric bicycles.
Specifications:
- Input Voltage: 48V
- Wattage: 800W
- Current Limiting: 35A
- Phase Angle: 120
- Under Voltage Protection: 41.5V±1V
- Case Dimensions: 176mm x 83mm x 40mm