"Theratrac Cervical Traction Unit, Medium 16""-18"". The Theratrac gently stretches neck muscles allowing the vertebral discs to realign, freeing the nerve root tissue from the pressure of the discs. Helps locked neck muscles to slowly stretch and relax, allowing misaligned vertebrae to resume their normal supportive position. Cradles the head and neck via a curvature in the neck portion of the device, as well as a special head rest section that is vertically pneumatic. Both the headrest and neck region, inflate with over 30 lbs of adjustable, neumatic pressure to create traction in the cervical curve."