Designed for swim training, either in the pool or open water. The jammers lifts your hips up like a wetsuit and helps you find the right water position. You will achieve same effect as using a pull buoy, but it allows you to kick and turn naturally. The jammers has a base of extremely flexible GLIDESKIN neoprene. 3 mm on back and 5 mm on front. It provides great mobility and minimum water resistance. Drawstrings at the waist. Unisex model.