Hamilton CapTel 2400i Captioned Telephone Large Touch-Screen Captioned Telephone with 40dB Amplification Includes Liberty Health Supply Microfiber Screen Cloth REQUIREMENTS: 1) Telephone Service - Can be analog, digital cable, DSL, VoIP, FIOS. Not compatible with digital PBX systems 2) High-Speed Internet (WiFi or Ethernet cable) 3) Standard electrical power DIALING: Traditional telephone keypad for familiar dialing and Captions can be turned On/Off at any time during a call with the push of a button (Captions available on calls within the United States only) TOUCH SCREEN: Large easy to read touch-screen display with Adjustable volume control buttons (up to 40dB gain) ANSWERING MACHINE: Built-in Answering Machine takes voice messages with captions Caller-ID capable and Phone Book allows you to easily store and dial more than 95 names/phone numbers