... Connect with phone set,PBX; -With LCD to show calling ID; -Suport G3 Analog F,battery. 900/1800MHz GSM FWT1803B ,with G3 Fax and LCD ... after connection to telephone set.3. LCD Display Time,Power, Phone number, Battery, Network, Working and Signal Intensity Indication4. Calling Support ... , PBX, billing machine, etc7. Available to connect with backup battery, and the stand-by time can reach 24 hours in ...