Imperium MobileLink, model 200ML, is a radio transmission environmental control unit designed for use by individuals with mobility or severe physical disabilities or spinal cord injury. The system communicates through a 2.4 gigahertz radio link, which transmits around corners, through walls, and across significant distances. The system consists of two components, a base unit and a remote unit. The base unit sits atop and plugs into a host environmental control unit, such as the Imperium 200H from InterAct Plus (not included) or environmental control units from other companies. The small remote unit attaches to a wheelchair. Control signals for this system are provided by any dual switch. Audio input/output for the included telephone, the spoken menu, menu beeps, or for a tape recorder or PC is provided via either a lapel microphone with small on-board speaker or stereo headphones, or a headphone/boom microphone combination. POWER: Uses the wheelchair's battery.