This Channel Master Cm-9521a TV Antenna Rotator System is both a drive unit and control unit, giving you a dual functionality that you can rely on. It is used to provide easy TV antenna positioning from a remote location through the use of an electronic control box and control unit, up to masts of 2 inch in diameter. The Channel Master TV antenna rotator rotation speed is one rotation per minute. It is made with a one-piece aluminum housing. The item features wind tested brake pads that give you a high quality output. It has easy push tab wire connections too. The Channel Master Cm-9521a TV Antenna Rotator System uses nonvolatile memory to hold locations during power failures.