The shackle is made of 304 Grade stainless steel which makes it perfect to use in outdoor applications where corrosion can ruin normal locks. Combined with the 2 inch shackle length, this padlock is versatile in any extreme outdoor use. The padlock also features double bumpers that will reduce scratching on surfaces like metal gates and doors or coolers and pickup storage boxes. The lock includes a 4 pin cylinder that resists picking and steel locking bolts to resist prying or hammering. Keyed Alike.