For testing network cables and installations for correct assignment and functionality. This device features a master and detachable remote unit, allowing for testing cables even over longer distances or in separate rooms. It checks lines in the cable for continuity, short-circuit, wire reversal, and defects. The connection test is displayed via LEDs for up to 8 individual wires and shielding. It is suitable for cables with 8p8c (RJ45), 6p6c, or 6p4c modular plugs. There is a switch for 3 modes: Off, On (fast test), and S (slow test). A common 9 V block battery is required for operation.