Make sure head immobilizer is taken apart. (1) Base plate, (2) head blocks and (2) head/chin straps. Place base plate against top of spineboard with attached straps stretched out. The straps attached to the base plate loop over and then through the handle running the strap in-between the board and the base plate. The run strap through and over other handle and attach strap to Velcro on base plate. Repeat with 2nd strap. Attach retention strap at top of base plate by looping through center hole of spine board. Attach head blocks to Velcro and place head/chin straps over blocks and loop Velcro ends through D rings on base plate. Securing the patient in the Head Immobilizer: Position the patient on the backboard so that their head is positioned in the middle of the base plate. Secure the patient on the backboard with restraining straps. Place the head blocks against each side of the patients head. When possible align the holes in the head blocks with the patient's ears so you can hear the patient. Loop each end of the forehead/chin straps through the D rings. Tighten as needed. The head immobilizer is vinyl coated and is both buoyant and waterproof.It can be left in place during X-rays.