The Leica Rod Eye 140 Classic receiver is designed to pick up the laser beam from a rotary laser. This receiver has a front and back LCD display for easy readout from either side. The laser detection window is 5" allowing you to easily find and detect the beam. Audio indication can be set to low and high as needed. The housing is rugged and includes protective rubber overmold on the edges and corners to soften the bumps and drops it receives on the job site. The unit also includes a grade rod bracket with integrated level vial. It will detect laser signals up to 4,430ft (laser dependent) and detects visible and invisible lasers in the 600-800nm spectrum. There are three detection accuracies of +/- .04", +/- .08", and +/- 0.12" to suit your application needs.