A CapTel 800 telephone (available at a reduced cost to qualified users in many states).
Your state must offer CapTel service as part of its Relay Service (see states that provide CapTel service).
Analog telephone line(s). DSL supported if appropriate filter in place. Not compatible with PBX systems unless analog port available. Not designed for use with digital cable, VOIP or cellular telephone services.
Standard electrical power (AC adapter plugs into standard wall outlet).