The Ameriphone Digital Cell Phone Compatible Combination TTY/VCO, model Q90D, is a portable text telephone or TT designed for use by individuals who are deaf or hard of hearing. It plugs into most cellular and cordless telephones and features a full-size keyboard with 68 keys. The large, high contrast two-line display tilts for optimal viewing, and backlighting is provided to make reading easier. The Dialogue LVD (see separate entry), a large visual display, can also be used with this model. Hi-Speed Code sends text at twice the standard speed. Other features include a built-in microphone for Voice Carry Over (VCO) calls, two programmable text greeting messages, and redial, hold, printer, and flash funtions. WARRANTY: This product has a limitied one-year manufacturer's warranty.