Monoprice 100820 CN50M Terminator Active with LED (100820) Terminators reduce interference on a system by preventing RF signals at the end of an open line from being reflected back They are placed at the end of a daisy chain line to match impedance and minimize reflection An active terminator is a one with a voltage regulator to compensate for variations in power This external terminator is single sided and features a Centronics CN 50 pin male connector and LED indicator light