Stopper Set Classic #5-11. Black Diamond STOPPER SET CLASSIC NO. 5-11 are racked on an OVAL WIRE carabiner.. They are essential for every trad rack, designed with a transverse taper that permits sideways placements in flares and shallow seams. Anodized by size, they're quickly identifiable and rounded edges make for easy removal. Each stopper is equipped with a durable, galvanized steel cable.