The Muc-Off Crank preload ring is an extremely durable, precisely crafted CNC component made from 7075 aluminum alloy. It allows for accurate adjustment of the preload on the lower bearing movement. This adjustment helps eliminate frame flex and play in the bottom brackets, improving the lifespan of the bottom bracket bearings and providing a quiet riding experience. Available in classic anodized colors for added aesthetic appeal. Compatible with left cranksets of mountain bikes, gravel, or road bikes that feature 30mm cranksets from SRAM, RaceFace, or Easton, or SRAM DUB 28.99mm spindles.