Edelrid didn't call this Carabiner Bulletproof because it can take a shot, so don't even try falling on a carabiner with a hole in the middle, but because its steel insert provides the durability that project-loving sport climbers need. Unlike aluminum, steel prevents premature wears, burrs, and sharp edges to stay solid for seasons of punting and lowering, but one steel carabiner weighs enough to feel like it'll pull your harness off your waist. That's why Edelrid made the Bulletproof only out of steel where the rope touches, while everything else is superlight aluminum.