Features & Benefits: Complete with Amplifier probe and Tone generator. Wire trace (RJ45 & RJ11) and continuity test (RJ45). Identify telephone line condition & plority. Built-in speaker with sensitivity control. A LED light assists use in dark environment. Power requirements: DC 9-volt battery. Certification. Passes RoHS, FCC, and CE compliance testing, and Noyafa is certified to the ISO 9001 standard. 100% Affordable. Manufactured in China and a lot cheaper than competitor products with similar quality.