3mm nylon II neoprene. Glued and blind stitched inside and out. YKK #10 Brass zipper. Low profile water sealing zipper design. Dual zipper pull loops. ZIPPER: YKK #10 brass zipper. Akona's unique zipper design utilizes dual rubber strips to additionally seal the zipper opening when closed, creating a water resistant closure. In addition, Akona's low profile zipper flap folds over a closed zipper to further seal and secure the zipper in its closed position. The reinforced pull loop at the base of the zipper makes self-donning of the suit fast and easy KNEE PADS: Akona's uniquely designed and stylistic knee pads provide exceptional grip and durability. Unlike the stiff rubber knee pads utilized on other suits today, Akona's revolutionary AKONA knee pad material is fully flexible, and has a hydrodynamic low profile. SHOULDERS: Akona's Grab Shoulder material provides superior wear and scuff protection. Designed to grip a buoyancy compensator to reduce shifting, the Grab Shoulders create a snug and movement-free fit. The unique pattern of the Grab Shoulder material also prevents excessive stretching of the suit when hung to dry.