1. To convert GSM signals into LAND LINE. 2. Output over telephone or can be connected to EPABX 3. Can put any SIM like AIRTEL/VODAFONE/BSNL/IDEA 4. with CALLER ID compatible. 5. Plug & play device. No need any programming. 6. Use ful for reducing your telephone bills. 7. Available in two models with/without Display.