Provides quick and easy verification of RF and IR transmitter signal with audible beep and LED light. RF example: key FOBs, garage door openers, tire pressure sensors activation tools, aftermarket key FOBs and remote starters, etc.. IR example: IR printer ports, in-vehicle audio/video remote controls. general IR remote control and signals. Designed to detect RF signals between 0-900 MHz. Operates on 9V battery (included)