This BornToSwim® Pull Buoy is a great tool for improving swimming technique. Simply place the pull-buoy in between your thighs to prevent your legs from moving and focus on proper body rotation, early vertical forearm (front catch) or a correct head position. Pro Swim Tip: Position the buoys between the ankles to make it a bit tougher (note: keep your lower back flush with the surface of the water). Or place it in between the knees while practicing an efficient breaststroke kick with knees in and heels out. Product Details: Colors: green and yellow, pink and yellow, blue and green Size: 22 x 10 x 7.5 cm Material: EVA Foam