Made of high-quality stainless steel, the Petzl Coeur Anchor Bolt Stainless Steel Hanger & Bolt 10 or 12MM 20-Pack from OmniProGear is ideal for typical exterior uses. This 316L stainless steel assembly consists of a hanger, bolt and nut and resists corrosion. A wide ergonomic connection hole makes carabiner clipping easy and allows two carabiners to be installed at once. The thick hanger and the connection hole's rounded edges limit wear on connectors. The hanger's anti-rotation system employs a textured back to keep the hanger from turning as the anchor is installed or when it's heavily laterally loaded.