Features: Provide fast and efficient communication line checking function, which is convenient for users to carry out troubleshooting and maintenance of telecommunication Networking. Supports Unicom, Tietong, Netcom, Telecom and other carriers Networking line testing, widely used . Simple to operate, easy to use, suitable for all skill . Multiple functional maintenance and line checking tool, can be used for different types of communication line testing such as telephone lines, broadband lines and so on. . Highly accurate test result, accurately display line status, help users quickly locate the problem.. Specifications: Size：about 134x49x27mm/5.28x1.93x1.06in Component:ABS Features： 1. 50 groups of incomes calls, 16 groups of outgoing calls 2. 16kinds of music ringing option 3. Caller identinination and call time record 4. Double standard caller display 5．Collection time can be selected 6. Incomes and outgoing call number search, call back, deletes function 7. Real-time date and day of the week display, display brightness adjustable in 5level Package Includes: 1PC Communication Line Checking Machine note: Due to problem of lighting,there might be tolerances in product, please understand. Please allow 0-1cm error due to the measurement