• Wear safety glasses. Your Multi-Code Radio Controls are designed specifically for the remote control of industrial door or gate openers and to give years of dependable service without adjustment. SELECTING A CODE The code is determined by the positions of the 10 small switches numbered 1 through 10 located on the receiver board. To gain access to the switch, remove the top section of the case. Any combination of ON ( CLOSED) or OFF (OPEN) positions can be selected by using a small screwdriver