Simpson Redline ShoeThe Simpson Redline Shoe is SFI approved for racing and features a performance enhancing, streamline design that is comfortable and pliable.SFI 3.3/5 CertificationManufactured of top grain leather and fire retardant Nomex®Hidden lacesTextured bumper panelsSingle large Velcro ankle strapThe Adrenaline is made from Satin suede with a fleece fire retardant lining and is SFI 3.3/5 approved. Triple layer interior toe area for added wear protection with additional reinforcements in the heel and a speedfit lace closure. The low cut Achilles support gives maximum flexibility and comfort. The non-slip, super-sensitive PU sole with posi-grip traction keeps you grounded.