Tricycle Motorcycle,Fuel Powered Three Wheeled Motorcycle,Convenient Fuel Tricycle,Convenient Three Wheeled Motorcycle CHONGQING ZONGWO VEHICLE INDUSTRY CO.,LTD. , https://www.zonlonmotor.comPrinciple: When power is on, the electromagnetic coil generates electromagnetic force to lift the closing piece from the valve seat and the valve opens. When the electric power is off, the electromagnetic force disappears. The spring presses the closing piece on the valve seat and the valve closes. Features: In vacuum, negative pressure, zero pressure can work normally, but the path generally does not exceed 25mm. As shown: