CHECK THE SIZE CHART (in the image section above) The men's Speedo Proton Fullsuit wetsuit from Speedo is developed for beginner triathletes and passionate openwater swimmers. For speed in the water and the transition out of it, the Speedo Proton wetsuit range uses light, flexible, hydrophobic materials, suitable for strong swimmers looking for an extra edge on their performance. The Fastskin Proton Wetsuit has been developed with Y38 (Yamamoto 38 cell neoprene rubber) a well balanced foam providing high buoyancy and flexibility that makes it one ofthe most versatile neoprene available. Maximotion+ technology in the single piece chest and shoulder panel means your stroke is as unrestricted as possible. Core stabilisation reinforces the core, enhancing the connection from the torso to the upper and lower body, to promote a more efficient stroke. Neoprene construction, thicker on the abs straps(3,5 mm), for support and un matched buoyancy. Improved water tightness of the cuff compared to previous Speedo wetsuit provides a more streamlined wrist and arm profile. Slatted cut leg openings allow for easier suit removal Features:Maximotion+ continuous 1.5mm neoprene chest panel increases arm and shoulder freedom of movementYamamoto NANO-SCS provides lower surface frictionCollar shape designed to reduce rubbingNeoprene thickness: 2 to 4 mmTemperature range: +/- 20°CStrategically placed seamsRevo Zipper construction is easy to fit and allows a fast transition from swim to bike Neoprene thickness:Front hips and thights: 4 mmChest panel: 3 mmForearms: 2 mmTop of the back: 2 mm