DURACAP™ Reinforced Materials, Deeper Knurl Texture On The Toe Bumpers, And Higher Sidewall. Reconstructed With A Molded Heel Counter And Internal Tongue Straps For A Locked-In Fit. SickStick™ Gum Rubber Compound. POPCUSH CUSHIONING Cushioning And Impact Protection. POPCUSH™ Energy Return Footbeds Protect Your Feet.