This hand-held LAN network connection tester is designed for RJ11, RJ12, and RJ45 cables. It accurately indicates connection errors, short circuits, and open circuits. The tester features standard and slow speed display modes and includes both master and remote units. It is powered by a 9V PP3 battery (not included) and can test connections on RJ11 and RJ45 cables with twin speed. The master and remote boxes allow for testing of up to 300m and can handle 48v for POE Networks. It is suitable for CAT6, CAT5, and CAT3 cables, with an LED Indicator. Requires 1 x 9V PP3 Battery (code 38240).