Features: Input and Output Voltages: Electric speed controller input is 220VAC and the output voltages is 180VDC. Working Process: Electronic speed controller is a directs start with voltages, with the motor, miniature gear reducers, speed sensor and the composition of mechatronicproduct. Forward Reverse Connecting: Motor speed controller can do forward or reverse rotating by connecting M + or M‑. Good Mechanical Property: This motor speed controller is with good mechanical property and wide speed ranges. Simple Installation:This motor speed controller is simple for installation and use panel screw mounting. How to Use: 1. Before use, please set the external speed twist to 0 to avoid generating instantaneous high current and damaging controllers. 2. The back terminal alternating current indicates input voltages, M + / M‑ indicates power output to motor, P1, P2 is the emergencys stop terminal, when P1, P2 short connection then the motor stops running. 3. This product adopts built in fuses for over current or short circuit protections, such as fuses should be replaced with the same specification fuses after melting. The panel action switches only control the motor action or stop, not for power supply. Specifications: Item Type: Motor Speed Controller Material: ABS Input: 220VAC Output: 180VDC Appearance Size: Approx. 100x60x114mm / 3.9x2.4x4.5in Opening Hole Size: Approx. 81x53mm / 3.20x2.1in Installation Method: Panel screw mounting Power:250/400/500W Package Includes: 1 Piece Motor Speed Controller note: Please allow 1-2cm errors due to manual measurement,Please make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.