Linear DR / DR3A / DNR00011 Set is a single channel 310 MHz radio frequency. The DR3 operated using dip switch codes that are set by the owner where the remove and receiver match switch identification manually. Typically found on older garage door operators for a replacement radio receiver. Installation is simple were the receiver can mount directly onto the opener if your old opener has 3 screw terminals on the back of it. Manually align the 8 on/off dip switches on the remote control(s) to match the receiver. This is a 24 volt single device controller and remote set.