Rev Counter Board replacement. | Plug and play. | Rev Counter Board: Calculate the opening distance of the opener and solve the problem that your door cannot be opened correctly. | Please judge the fault location based on the buzzer sound: 3 beeps will be heard when the main arm is faulty, 4 beeps will be heard when the sub-arm is faulty. | Please sealing and draining during installation,avoid short circuit and failure to work caused by water ingress.