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. Dirt Rag Magazine's Editor's Choice. Light Lighter weight compound conforms to trail objects while still providing a happy balance between low rotational weight and reliability. 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. HG High Grip, 45a durometer, glue-like conforming rubber over a firmer 60a durometer supportive base for uncanny traction. TCS WTB's Tubeless Compatible System, sealant based tubeless system with improved bead shape Mountain 29x2.3 622 TBLS Bk/Blk 900 LIGHT/HG/TCS