Made from Yamamoto Smoothskin neoprene, the Zone3 Next Step 3/2mm thick buoyancy shorts will help you improve your body position when swimming. Comes with a comfortable waistband. Key Benefits: Improves your body position and swim technique. Designed as a natural feeling alternative to a pull buoy. Enhanced core support to aid with technique development. Can be used in open water swimming as alternative to wearing a full wetsuits (if the water is warm enough) Sizes available are XS, S, M, L and XL. Each set of shorts has a drawstring so they can be tightened to any waist size but Zone3 would recommend the size XS for waist sizes 26-28, S for 30-32, M for 32-34, L for 34 -36 and XL 36-38.