Material:PVCHow to use:1.When using the tractor， openings in the front， through fastening neck circumference size adjustment2.Tighten screw nut in the top of the item then inflated.3.A period of treatment need about 15 to 30 minutes，one or two times a dayAvailable Range:1.This product is suitable for the prevention and treatment of cervical spondylosis of nerve root type2.This product can remove fatigue， increase strength， enlarging space of cervical vertebra， modifying the positions of cervical vertebra， making the carotid artery unimpeded，Increasing the flow of blood to the brain.3.If discomfort occurs， should be used under the guidance of treatment