ALWAYS CHECK THE SIZE CHART (IN IMAGE SECTION ABOVE). SIZES PROVIDED ARE UK SIZES, BE SURE TO MEASURE AND CHECK THE SIZE CHART BEFORE ORDERING. The�Aquarapid Boy's Bat Trunks feature�a streamlined cut. The high cut and low waist fit results in optimal freedom of movement for the legs and hips and minimized fabric friction on the body. The Bat trunks are made of�highly chlorine-resistant, long-lasting DEFENDER fabric -�synonymous with outstanding breathability and providing a perfect fit when training. DEFENDER Fabric: Non-run fabric providing unique comfort and incredibly high chlorine resistance, remarkable elasticity, mildew resistance, enhanced sports performance, a soft feel and moving comfort. CARVICO: Guaranteed quality, reliability and constant technological research: italian fabrics by Carvico are designed to achieve the best performances, with full respect for the environment. Internal Lanyard: Inner drawstring waist for improved comfort and fit. TOPSWIM line: Costume training line designed by Aquarapid champions. Made with an extreme fitting, it perfectly meets the needs of athletes for training and those who are looking for products with a fashionable and fun look.