Continuity Tester Pro with Remote Probe - 

The CT20 is a Remote and Local Continuity Tester with one person operation for wire and cable testing. A bright flashing LED and loud pulsating beeper indicate local continuity. Remote continuity features the use of the remote probe, it does not tie-up two people when identifying and labeling long distance wire/cable runs. Flashing remote probe features two lead, bi-color (red/green) LED probe allows a single user to identify up to three wires or cables at a time for correct labeling with only one trip to the other end location - cuts down on multiple trips back and forth. Polarity verification features drives a 20mA DC current pulse through the wires or cables under test to the bi-color remote probe. This enables the technician to identify each of the wires under test at the other end of the cable run and eliminates the possibility of false high impedance readings.