The DHF incorporates ramped knobs for low rolling resistance and channel-cut knobs to increase gripping edges, giving straight-line control and precise cornering. SC Single compound casing for a durable, dependable tire. ST Super Tacky soft 42a compound . EXO equipped models feature Maxxis' EXO sidewall protection which help prevent puncture from sidewall abrasions. 2PLY Two full 60 TPI casings with reinforced sidewalls intended for Downhill riding. TERRA 3C Maxx Terra is softer and offers more traction than 3C Maxx Speed, yet provides better treadwear and less rolling resistance than Maxx Grip. TR Tubeless Ready sealant required. DD Double Down construction features two full 120 TPI casing layers reinforced with a butyl insert Downhill 27.5x2.3 584 TBLS Bk/Blk 65 1075 120 TERRA/TR/DD