Passive rock protection with three-point contact, wired stoppers are the classic solution for bottlenecks, shallow seams, and tapering cracks. 7075 aluminum alloy is durable yet has plenty of bite to stay put. Transverse taper increases surface-area contact to provide best placements in nonparallel cracks. Rounded corners allow easy removal. Anodized (colored) by size for quick identification. 793661019749 20081500012 225209