NF-868M：Features:1. Test open, short , cross, reverse connection and broken wire positioning.2. Capable to measure length of network cable, coaxial cable, telephone cable and USB cable.3. To quickly find the target wire or cable among kinds of wires.4. Anti-intecference when tracing cable on exchanger or Router. 5. Two scan modes: oridinary switch /PoE switch. 6. Functions of storage and memory for calibration data.7. Automatic delay power on-off and backlight function.