Test equipment can help to save you time and headaches when you're repairing electronics and components. Here are some important details for Greenlee Communications NetCat 100 Cable Tester. For Use With: Designed For Standard Tone Probes, But Compatible With Precision Digital Greenlee Tone Probes, Connector Type: RJ45, RJ12, F-Type, Features: tIA/eIA Standard Wiring Pair Verification. Detects Shorts, Opens, Reversed Polarity, Crossed And Split Pairs. Generates 3 Distinct, Selectable Digital Tone Patterns For Cable Tracing And Troubleshooting. Tracing Modes Can Be Adjusted For High Performance LAN Cables.Simple Testing Of LAN Wiring And Phone Lines. Warning Of Hazardous Voltages..