Designed to fit most corners and angles to secure hard-to-lock properly. Recommended for use with Master Lock medium and high security padlocks. Heavy-gauge hardened steel protects against cutting and sawing. Hardened Boron alloy staple withstands up to 8 tons of cutting force. Rolled edges protect against prying and conceal mounting screws. Hinge pins are hidden and are virtually impossible to remove. Accepts shackle diameters up to 7/16 in.