Unique adjustable collars. Combined with the Redi-ACE Mini, these 2 collars offer 14 sizes, ensuring that patients can have the most effective and accurate fit possible. Made from radio-translucent materials, each collar is packaged completely flat, has a unique automatic flip-up chin, and incorporates latches that allow the rescuer to size it as accurately as possible to the victim’s neck size. Two safety lock buttons hold the collar in place when adjusted.