Thank you for your question. The KX-TGF775S is a newer model, released in 2019. The difference between it and the KX-TGF575S is that KX-TGF775S has Answer by voice command, a feature that allows you to answer incoming calls automatically with your voice. Another feature that this model has it is Automated call block, with this the unit screens incoming calls before ringing for allowed calls or ends the calls without ringing for calls identified as robocalls, telemarketing calls, or
other undesirable calls (Caller ID subscribers only). The unit will play the greeting message for
automated call block and prompt the caller to enter an access code in order for the unit to identify whether the call is automated.