I was watching some of Hal Ruzal's lock grading videos, and noticed several times him praising these U-locks where the shackle has a square cross section instead of round, and it makes sense. I can see how that can resist bolt cutters. However I didn't see anything like that from Kryptonite, at least not when I last looked. Who makes locks like that? Onguard Locks don't have them, either.