The CT20 Continuity Tester Pro features single-user remote or local continuity testing and wire/cable identification capabilities, eliminating the need for someone to be at both ends of the wires under test. The instrument is a two part system consisting of the master continuity tester/transmitter and a two-lead, bi-color (red/green) LED remote probe. The master performs continuity testing and remote wiring identification and the probe allows for remote testing when identifying cables, verifying polarity or labeling long distance wire/cable runs. The probe features a bright pulsating bi-color (red/green) LED, reportedly visible even in bright daylight areas. Its LED flashes green when wiring is correct and red in the case of reverse wiring is. The master tester/transmitter employs bright flashing LEDs and a loud, pulsating beeper. The two-part configuration allows a single user to identify up to three wires or cables at a time for correct labeling with one trip to the other end of the wire or cable location. EXTECH INSTRUMENTS, Waltham, MA. (781) 890-7440.