CL-NT-08Cable Tester Tracker Tone Generator for TelephoneProduct detailsThis instrument is designed to identify and trace wires or cables without damaging theinsulation, you can also use it in checking for short circuit and locating open circuit andso on. In addition, it can also be used to identify some states of telephone line so that itis more convenient to install, debug, and maintain telephone lines, There are a Senderand a Receiver included in the instrument. 1. Provides an adjustable volume control 2. Compatible with all common tracing tone sources 3. Easy cable connection with either RJ-45 jack, patch cord, or alligator clips 4. Receiver & Sender 5.Testing polarity of phone lines 6.Tracing a wire 7.Finding wires buried behind drywall 8.Test whether a cable is interrupted 9.Find interrupts in cable10.Power:9V battery (6F22)