Multi Sport FPS Flat Protection System; Inverted tread design reduces rolling resistance enabling greater; 68a durometer center tread / 58a sides for enhanced cornering; Reflective sidewall options (CTRREF, CTR-1.5REF); Serfas most popular and best selling tire; Serfas Drifters give you the confidence and freedom to ride almost any environment; Capable dual density tread provides speed and grip across various surfaces