... optional 2.proper door area:4sqm-9sqm. 3.high quality Motor feature1.Single chip microcomputer control--one-button remote control ,will ... according to open door--stop--close door--stop instantly.2.Dc motor can operate under low noise condition. soft start, slow stop ... , can detect power, which can protect the motor and extend the using life of motor. 3.Has the function of overload detection ...