16 to 18mm shackle diameter, high grade steel, high level key systems and top level* test approvals
Of course any lock can be destroyed with the right tools under ideal conditions. Whether or not the lock can be broken is irrelevant. Relevant is this. Will a thief even attempt or will he move on to an easier target? Will it just take too much effort in time and required tools?
(* some brands stretch the truth on their test seal approvals)