Telephone Line Tester ST230 Lineman Test Tool Sets Checker Butt Set Tester Brief Introduction ST230 is a portable and intelligent line fault tester which is designed following human engineering theory with the appearance style like barbell, adopting advanced technologies such as intelligent CPU, IC & SMT technology. It integrates various kinds of functions such as telephone and line performance test to be the one. Inner chargeable NI-MH battery can works about one week after full charging; the shell is made of the new type of material and it is solid. Main functions 1. Dialing, Receiving, Redial 2. Incoming call number display 3. Mute function 4. P/T transfer function 5. High DC voltage indication 6. AC V & DC V test 7. Insulation test 8. Open test 9. Earth insulation 10.Call user & talk 11.Phone test 12.Check wire pairs 13.Monitor function 14.High AC voltage alarm 15.Under voltage self-checking FEATURES: 1. common telepnone(dial,talk,hook) 2. store phone number 3. caller ID 4. Tone/pulse dialing 5. Mute function 6. High AC voltage warning 7. DC voltage disply 8. Insulation value display 9. Earth insulation value display 10. Line break display 11. Check wire pairs 12. High resistance monitoring 13. High AC/DC voltage test 14. Low voltage warning 15. LCD display in English 16. Handset operation Key specifications: 1. DTMF applying to GB/T15279-94 2. Caller ID For FSK/DTMF 3. High AC voltage alert