Zipper can be used for most sizes, but will not zip up for extra large chest/torso sizes over 50 inches because of the 2 sets of front buckles on vest.
This vest is covered with PALS (Pouch Attachment Ladder System) webbing for numerous modular pouch attachments and has fully adjustable shoulder and waist straps. There are two mesh pockets inside the vest with Vel-cro closures, a zippered front closure, and two quick release buckles.
Adjustable size from small all the way up to 50 inch waist.