AKONA has updated its flagship steamer with a new type of limestone-based neoprene that is 25 percent more flexible for even greater comfort. Other performance features include a longer back zip to improve entry and exit, upgraded knee pads for increased durability, and a redesigned hook and loop neck seal. Environmentally Friendly Neoprene Rubber Design Non-Petroleum-Based Neoprene Limestone Over 99.7% Calcium Base Neoprene Upgraded in Every Sense: Material, Design, Fit, Fashion & Comfort 25% More Stretch than Previous Version Unique Lamination Process Nylon-2 Material Extraordinary Flexibility and Stretch Capabilities Nylon Weave Capable of Withstanding Harsh Elements of Diving Most Comfortable & Best Fitting Wetsuits In-Their-Class #10 YKK Marine-Grade Brass Zipper Slider Full Length Delrin Back Zipper Zipper Pull Leash for Easy Self-Donning/Doffing Zipper Dam: &';Skin-Out&'; for Added Seal and Reduced Water Flushing Durable Reinforced Laminated Knee Pads All Seams Glued and Blind Stitched for Strength & Durability Textured Shoulders: More Secure Fit of BCD, Prevent Piling of Shoulder Surfaces Sizes: SM 5/6 MD 7/8 LG 9/10 XL 11/12 2XL 13/14 3XL 15/16