Wide knobs down the middle provide control under braking and L-shaped side knobs assure support when carving loose turns DC - Dual Compound tread provides a lower rolling resistance center paired with extra grip for the corners EXO - sidewall protection which helps prevent puncture from sidewall abrasions TR - Tubeless Ready - sealant required Tubeless 27.5x2.4 584 TBLS - Fold Bk/Blk 55 60 DC/EXO/TR No