Save money when you buy the Classic Stopper Set from Black Diamond. This convenient set includes Stoppers #5 to #11 which are the most frequently used sizes for most climbing areas.
Black Diamond anodized their Stoppers for easy identification. Stoppers are the foundation of any climbing rack and these are the standard wired, wedge-shaped nuts for thin-crack protection. Black Diamond designed a transverse taper into the Stopper which permits good sideways placements in flares and shallow seams.
This feature opens up previously unprotectable cracks, and makes Stoppers significantly more functional than other wedge-shaped nuts. The nuts are easier to remove since Black Diamond rounds-off the sharp corners that cause nuts to get hung up on crystals and irregularities inside the crack.