The telephone is designed for use behind a standard analog phone line (landline/POTs or VoIP) or registered PABX system.  This auto-dialer emergency phone can auto dial a pre-programmed phone number e.g. 911 and/or also receive calls (ringer is adjustable).  The telephone is designed for use behind a standard analog phone line (landline/POTs or VoIP) or registered PABX system. Note: This telephone cannot be used with digital PABX station ports. Data port – Provides a convenient extension of the connected telephone line for connecting a device such as a modem, fax, or answering machine.   Features include: Auto dials pre-programmed phone number when handset is taken off-hook. Hearing aid-compatible handset with volume control — Volume controls for the handset and speakerphone. Volume may be set to one of four levels. Audible Incoming call Ringer Volume Control (Switch: Low | Hi). Desk or wall-mount option. Visual incoming call alert led lamp – Also functions as message waiting light for compatible with high voltage neon (90dc volts) and at&t/lucent/avaya low voltage led message waiting light systems (20 to 25dc volts). Dimensions: 8.75” (l) x 6.0” (w) x 2.75” (h). Weight: 3.1 lbs (14.06kg). Certifications: FCC Part 68, FCC Part 15 & UL 1459 Ref. ADA/FCC Hearing Aid Compliant. One (1) Year warranty. > Model: HQ-Cetis-Bck-HD> Manual Auto-Dial Programming > Up to 25% volume discount available (3+), please contact us for details.