The square-lugged open-tread pattern offers stability in loose or wet terrain while the stiff outside knobs grip at lean angles like nobody�s business. Updated tire profiles provide a smoother transition from centerline to side knobs and improve predictability while cornering. Improved knob shapes prevent knob flex by reinforcing the specific areas that counteract cornering and braking forces . Updated siping eliminates knob squirm while also increasing traction on wet or rocky terrain. Tough - A double layer of light casing TCS Tough tires are composed of two full layers of casing bead-to-bead leaving no area unprotected on our burliest tires. FR - Fast Rolling with WTB`s Dual DNA rubber compound that optimizes efficiency traction and durability A firm long-wearing centerline tread with softer side knobs. TCS - WTB`s Tubeless Compatible System sealant based tubeless system with improved bead shape . TT - WTB`s new triple compound TriTec featuring a hard base level medium center knobs and softer shoulder knobs for improved traction and performance. EBIKE25 - has achieved a passing rating for use with E-Bikes up to 25kph