The Network Probe for TC-NT2 Tester from TRENDnet is an ergonomically designed device that comes with an adjustable volume control and signal LED for enhanced accuracy in noisy environments. It is an easy-to-use amplified inductor and tone probe used for tone tracing and line testing. Featuring a simple push button, the Network Probe provides an easy operation and conserves battery power. It also features a ring/tip polarity test indicator.