A device used to immobilize the head and cervical spine following vertebral injury or surgery, designed to provide inline traction of the cervical spine while allowing for a moderate amount of functional independence. The halo vest consists of three parts : 1 ) t he halo, which is secured into the skull through the use of four pins or screws; 2) the vest, which is worn over the shoulders and trunk to support the weight of the halo, skull, and cervical spine; and 3) four metal bars that connect the halo to the vest.