Product Description Made out of 100% Silicone - The Nike Fin was designed with a shorter fin blade that enhances your efficiency and speed of kicks. The ridged areas on the side of the blades designed in conjunction with softer more flexible areas provide the ideal comfort while helping to produce maximum propulsion. The open toe box with grooves at the tip of the blade ensure a superior fit. The Short Fin blade enhances efficiency and speed of kicks while the Rigid Areas combine with a flexible blade for maximum propulsion. Features a Comfortable open toe box with grooves to provide a superior grip. 100% Latex free