The HOOTS is a High Output Optical Talk Set designed to work with multimode fiber, and will automatically adjust the volume to compensate for fiber loss over a 20 dB range of input light power. Two units are included with each set; one for each end of the fiber pair that you use to communicate. It uses our light source technology to convert your voice into optical signals. The HOOTS is a reliable alternative to wireless communications systems within a fiber optic network environment due to its range, security, and electromagnetic immunity.