Kryptonite Keeper Standard Anti-Theft U-Lock, Heavy Duty, 12mm Shackle, Black, Combination Lock, Lifetime

Great lock. Great company. Company even sent me additional keys. I did have one problem. There is a clasp for hanging lock to bike. It moved and i could lock device. My bad. I quickly saw that piece was easily movable and everything works well!!

Solid lock. Had to replace another one after someone tried to steal my bike by twisting the U lock. They tried again on this new lock, and while the lock is compromised now, they couldn’t steal the bike which is what counts. I’m buying again, but will keep the bike locked inside at night now..

This works great and slides right in to the side of my bike. No one is getting through this thing and it’s worth every penny.

I use this lock to secure my bike in our building's private garage and for rare quick stops so I didn't need anything crazy heavy duty. This works well for that. It does rattle a little when using the frame mounted holder when I am riding over rougher surfaces, but not too bad.Update 6/7/23: the plastic frame mount broke after about 1,500 mile of riding on paved bike paths. Replaced it with a kryptonite mount they sell separately and that seems better made, but still plastic.

Does it's job and keeps my bike locked up. I do sort of wish I sprung for the larger version because on some racks it's really hard to get the lock around the stand, tire and frame...but overall, it does what it needs to.

The lock is kinda finicky but otherwise a sturdy quality product

The locking mechanism is faulty and after using it for several weeks, it will no longer lock due to the keys. I wish I could return and get a refund.

This lock fits perfectly in the holes of unistruct metal brackets and rails. Easy to install and remove on a fixed, secured asset with a custom security frame.