Add up to four inches of Additional length to your farmer wetsuit or add years of use to growing teens' wetsuits. 3 mm neoprene with three adjustable snap placements. Oldest Design: Works with wetsuits with silver snaps Old Design: Works with wetsuits with black plastic snaps and with rough (hook) portion on the chest panel and fuzzy (loop) portion on the shoulder snap New Design: Works with wetsuits with black plastic snaps and with the fuzzy (loop) portion on the chest and rough (hook) protion on the shoulder straps.