MTB rear derailleur Sram Gx Dh 1X7Spd X-Horizon Medium Cage BlkWe understand that the gnarly line requires a lot more concentration than a supermarket ride.That's why we packed the GX DH 1x X-HORIZON rear derailleur with features that won it the world championship, and priced it more in line with Wednesday night championships.It's a DH derailleur that's easier to change, incredibly precise, and minimizes unwanted chain slap noise, so you can focus on the sweet feeling of getting your line right.GX DH - Go for it. X-ACTUATION for precise and reliable 7-speed performanceFully compatible with the SRAM X01 DH drivetrainX-HORIZON design reduces shifting force, ghost shifting and cage rattling12-tooth X-SYNC pulley wheels7s Cable pull ratio Exact actuation MediumMaximum tooth 28Sheave bearing material SteelCage material (RD) in Aluminium