McKesson Rigid Cervical Collar Preformed Adult One Size Fits Most One-Piece / Trachea Opening Adjustable Neck Circumference (1220096_CS) 50/CSUse to immobilize an injured person's neck and maintain its proper alignment. Height adjustable design features neck length size windows indicating four size options, ranging from "no neck" to tall with a colored indicator denoting set size clearly Sizing is easy: Simply measure adult neck using finger widths and match to the collar to determine the appropriate size. Dual locking tabs on either side of the collar Locking mechanism and adjustment