In quick summary, it looks like a large, built-in U-lock with the frame itself forming part of the U. Not un-stealable exactly, but rather a deterrent in the se

In quick summary, it looks like a large, built-in U-lock with the frame itself forming part of the U. Not un-stealable exactly, but rather a deterrent in the sense that using traditional U-lock-breaking methods like a carjack could damage the frame making the bike worth less(or nothing). You'd still need to secure the tires, though, too. I can't tell if there is a built-in part of the U-lock that allows for threading a cable through or anything like that. Typically what I see is something like U-lock around the rack, front tire, and frame with a cable threaded through the U-lock and through the back tire. Not invincible either, of course, but much more work and therefore more of a deterrent.