Protecto Shield® ProLock® Headgear with Ratchet Adjustment and Sweatband ORS NASCO Designed to efficiently conduct current Designed to efficiently conduct current through detachable type connection Cam action design allows lock in with a twist and pulls the two halves tightly together Metal parts are precision machined from heavy brass extrusion once applied in areas of high ambient temperatures Class H temperature rating Constructed of durable thermoplastic Heat resistant browguard prevents fluids from getting inside the visor Ratchet knob enables tension adjustment and visor positioning Visor (not included) attaches easily