The CapTel 840 is a voice carry-over telephone. This telephone the text that is being communicated over the phone. This product can transcribe audio into text. Technical specifications include: transcribed text can be deactivated at any time, voicemails are transcribed, font sizes and colors are customizable, compatible with wifi, caller ID. speed dial for people one may call frequently, the volume of phone is up to 40dB. Individuals who have a hearing, cognitive limitation that requires them to access phones to accomplish essential job functions may benefit from this device.