Network Cable Tester Multifunctional Ethernet Signal Cable Tester with Headphone Wire Item Type: Network Cable Tester Material: ABS Transmitter Battery: 6F22 9V Battery x 1 (Not Included) Receiver Battery: 6F22 9V Battery x 1 (Not Included) Interface Type: RJ11, RJ45 Flashlight: Equipped with Flashlight Network Cable Searching Function Telephone Line Searching Function: Yes Network Cable Verification Function: Yes Power Cable Searching Function: Yes DC Voltage Level Testing Function: Yes Low Voltage Prompt: Yes Single and Dual Sound Switching: Yes Open Circuit and Short Circuit Testing Function: Yes Illumination Light, Shield Line: Yes Auto Shut Off: Approx. 1 hour after power on, the cable tester will automatically enter the shutdown state. Earphone: No interference when inserted in noisy environment.