Brass covered laminated steel body for higher strength and resistance to the elements.| Tough cut boron carbide shackle is 50% harder than hardened steel.| The patented octagonal shackle is harder to grip by bolt cutters.| Increased shackle clearance for a broad range of applications.| Professional grade ball bearing locking mechanism provides maximum pull and pry resistance.| The laminated steel covered padlocks have a weather resistant brass cover, to protect the lock even in extremely bad weather conditions.| 4 keys included.