Master Lock Excell® Laminated Padlock features a laminated steel body for maximum strength and reliability and is surrounded by brass and zinc outer case for maximum weather resistance. The octagonal shaped shackle is not only near impossible to grip with bolt cutters but is made of Tough-Cut™ boron-carbide, 50% harder than hardened steel, offering maximum resistance to cutting and sawing. The 4 & 5-pin cylinders prevent picking and the dual locking ball bearings provide maximum resistance against prying and hammering – requiring both sides of the shackle to be cut to open.