1. A Patient Operated Selector Mechanism (Possum) has been described in detail.2. These mechanisms permit control over electro-mechanical devices by patients with high cord lesions or with extreme disability from other causes.3. Any residual muscular power may be used for control but the mouth is preferred for the high cord lesions.4. The research indicates that a high degree of control efficiency is possible. Systems now in use should permit control over typewriter and other keyboard devices at normal speeds.5. Systems under consideration may permit the re-employment of such patients on a competitive industrial basis.