With ropes being such a precious commodity these days, you want to do everything you can to preserve them. The Stubai HMS 3D has a unique shape that keeps the rope from rubbing the rock face, thus prolonging the life of your rope. With the precision engineered curvature of the biner, your rope will be protected no matter how the biner is positioned. The 3D's locking gate has a brass lock and precisely aligned threads for quick and easy locking even with gloves on. The 3D has a red anodized coating that helps it stand out in the rack and protects the biner from excessive wear.