4-Section Collapsible Anti-20-ton Hydraulic Shearing Super-B Lock Cylinder 30.3-Inch Alloy Steel Heavy Duty Lock with Bonus Mounting Bracket for Mountain Bikes, Electric Vehicles, Motorcycles.

Loved the construction and strength of this product. The lock collapses neatly and mounts to the bike. Any thief will just move on to the NEXT lock. The key, however is in question. There were three keys included, fortunately, but the first one busted immediately with little turning force applied. I have used care with the other two, and have had no problems, but if someone else were to use this lock, they may break as well.

If you want to protect your bike, this is it. I got it when promised and the lock provides the protection I need. The only down side is the weight, the protection makes it worth it.

a bit heavy but works well

Unique construction that I like better than the typical U-lock. Not only is it larger, it also bends to fit stands that might not work well with a standard U-lock. It seems to be well constructed and, so far, I haven't had a bike stolen while using it. (If my bike does get stolen, I'll be back here to update this review.) My only complaint is that it can be a little awkward to fold, but that's not a big deal. I'd rather have it be a little awkward so long as it works.

Great Lock! This is much easier to bring along on rides because it attaches to my bike. So far, so good! I still have my expensive electric bike.