interested

Not quite sure what you mean; any lock can be defeated by a determined thief with enough tools; diamond cutting blades on angle grinders or similar can cut though all practical bike locks. The Granit 54 is better than most locks; it is so stiff you have to cut it two different places to get it off, it is so strong you can't use a 6 foot steel bar to open it without destroying the bicycle frame at the same time, AFAIK it is rated to 10-12 tons of separation pressure, so I don't know of a portable hydraulic jack small enough to be carried in a backpack that can open it, AFAIK no one has succeeded in lock picking it. AFAIK, no easily portable non-motorized tool can defeat it within a reasonable time frame. This really reduce the amount of bicycle thieves that would steal it, since most bicycle thefts are done by opportunistic prowlers, using cheap and easily portable tools.

While angle grinders or similar can cut it, it can be quite difficult to do. Most youtube videos showing people cutting bicycle locks, aren't done on locks in actually use on a bicycle, but on locks safely in vice grips or similar. The point is that when people use angle grinders to cut sturdy steel bars, they almost always overshoot when going through, but the bicycle frame is instantly ruined if the cutting blade touches it. So not so easy to do IRL.