THICKNESS - The body is designed using 3mm Syprene neoprene on the front and back for buoyancy and warmth. While the 2mm neoprene on the underarms and crotch panels offer maximum flexibility when swimming and running. MATERIALS - The front is constructed using Syprene neoprene which has a tough surface treatment that protects the suit surface from minor abrasions caused by rocks, sand or gravel during transitions. The back, underarms and crotch panels are made out of extra-stretch double-sided nylon for flexibility and water speed. CLOSURE - Long front single-zip to help get the suit on and off. You can also leave the upper part of the zipper open during the run to improve cooling and ventilation. Comes with an emergency whistle built into the zipper pull. STORAGE - This suit has a lot of pockets so you have room to store everything you need. It has two large inner chest pockets where you can store your emergency kit, map and nutrition and one large back pocket with a zipper. LINING - This inner lining is smooth and comfortable against your skin and helps store body heat. Color Black Size Map Large Brand Name Synergy Sport Type Swimming Sleeve Type Short Sleeve Closure Type Zipper Manufacturer Synergy Material Type Neoprene, Nylon Item Thickness 3 Millimeters Age Range Description Adult Manufacturer Part Number SYN-WTSUT-00AJ-W-02-SRUN-SS-SM