Key Features No NBN nor Fixed Line Required Back-up Battery Packed with all the Simple Features with Dual SIM and Big Buttons! SOS Emergency Button 4G VoLTE (LTE-FDD :(B1)/(B2)/(B3)/(B7)/(B8)/B20/B28AB 3G 850/900/2100 NANO SIM socket  3 x Photo keys Talking keypad / caller ID (talking number/user recordable) User recordable SOS message  500 phone book memory 90dB Loud ringer User changeable ring tone +40dB Amplification receiver volume with Led indicator Big button Big dot matrix display (128x 64) 80 call log (time/day of call) 200 SMS messages  Real time clock (12/24 Hrs. display) New call indication: LED and icon Caller ID memory call back 2-way speaker phone with LED indication Ringer indicator (Red LED) Hearing aid compatibility (ETS300381 prefer range) Bluetooth (support Bluetooth headset) Desktop and Wall mountable 3.5mm Audio in out socket