SFI 3.3/5 certified ensuring proper levels of safety and compliance on track Woven Nomex lining contributing to our SFI rating along and greater comfort Suede leather exterior with double stitched heel and toe reinforcements for increased durabiliy and shoe frame integrity Industry leading thin sole with specialized rubber compound optimizing pedal feeback and foot positioning Vented leather for optimum breathability Low slung ankle strap for increased ankle maneuverability Fit. Form. Function. These are the 3 principals that went into the development of these racing shoes. Track Armour's HT6 Racing Shoes were designed and developed by our team of racing drives with over a decade in motorsports experience. A snug fit, with an industry leading thin sole, ankle flexibility and SFI 3.3/5 safety rating, our shoes deliver the right balance of driver safety and comfort.