The DHF incorporates ramped knobs for low rolling resistance and channel-cut knobs to increase gripping edges, giving straight-line control and precise cornering. DC - Dual Compound tread provides a lower rolling resistance center paired with extra grip for the corners TR - Tubeless Ready - sealant required EXO equipped models feature Maxxis` EXO sidewall protection which help prevent puncture from sidewall abrasions Tubeless 27.5x2.8 584 TBLS - Fold Bk/Blk 60 1120 60 DC/EXO/TR No