Made from opaque silicone, these fins offer the fit and comfort of the original Tech Fins, but with a cool new look. Symmetric blade, but remember, they DO NOT float! The foot pocket is nice and wide too. Excellent thrust. Manufactured from a revolutionary new material called T-Form, a super soft silicon based material providing unsurpassed comfort. In addition to this, Hydro has custom designed the T2 for both feet, adding to the extreme comfort. Hydro has also increased the power to kick ratio generated by the fin with the inclusion of the "POWERTUBE". The tube incorporates a funnel on the bottom of the blade to release water and sand trapped in the foot pocket. Incorporating HYDRO'S patented V-rail TECH 2 now offers unsurpassed Kick to thrust ratio. The rounded edges of the foot pocket ensure abrasion free tube-time, which tops off yet another impressive surf tool from the Hydro design team. The T2 fins are designed not only to flex laterally but also to TWIST during both Up and DOWN kick - emulating several sea animals' evolutionary aquatic propulsion methods. Those who know how to kick will benefit greatly from T2 and keeping their feet submerged will generate enough power for Bodyboarding and Bodysurfing in any surf conditions. XS (Mens shoe size 4-5) S (Mens shoe size 6-7) M (Mens shoe size 8-9) ML (Mens shoe size 9-10) L (Mens shoe size 10-11) XL (Mens shoe size 12-13) Note: These fins are below neutral buoyancy so we recommend purchasing a pair of fin savers. Swimfin Weight: 3.2 lb per pair Note: These run small, so if you are a 8.5-9, maybe consider getting the ML ones.