Stretch The Neck Muscles Better: The double-sided knob is different from other single-knob products, as if hs lift your head up from both cheeks with uniform lifting force, which stretches the neck muscles better than hold the chin up, makes the traction effect better. Different Traction: 3 POWER TRACTION 1) Side knobs adjust the height, stretch the neck muscles. 2) Rotate the back knob to fit the airbag to the neck. 3) Inflating the airbag, powerful Traction Air Belt pulling the vertebrae achieves 20 cervical physiological curvature repair. Effective Traction: Ergonomic of neck traction device helps to improve the blood supply for vertebral artery brain, promotes cervical physiological curvature repair. Please know that will bring the pain initially because of traction. Using 2-3 times per day help you get longtime relief from pressures of the neck pain, tension, muscles spasms. Applicable: Neck Height: 3.2-4.7 inch, Neck Circumference: 13.7 - 17.5 inch. 1) The doctor recommends traction stretching of the cervical spine (Diagnosis of cervical spondylosis by MRI, X-ray, or CT). 2) Long-term cervical spine compression pain. 3) Numbness in the shoulders arms. 4) Hear sound when rotate your cervical spine. 5) Traction the condyles of the cervical spine, not fix. Sturdy and Lightweight: The cervical neck traction device make by ABS and PC, light weight, breathable material is not stuffy, the upper lower pads can be removed washed.