The 75 Series are made of premium solid brass with double bolted hardened steel shackles with Nano protect plating for extra corrosion resistance. The 75IB Series are made of premium solid brass that is protected by pearl/zinc stainless-like chrome finish and comes standard with double bolted stainless steel shackles. It comes equipped with an ABUS dimple key cylinder with anti-pick mushroom pins. This gives it excellent resistance against picking while also adding thousands of key combination.