Kryptonite KryptoLok Series 2 STD w/4-Foot Flex Cable
The KryptoLok Series 2 STD U-lock is like a tough nut: you just can't crack it. Thanks to the 13mm hardened Performance steel shackle that resists cutting and leverage attacks, you get peace of mind while you run into the grocery store or lock up outside the coffee shop. Make sure your wheels are secure too when you loop the included 4-foot flex cable through them, and secure it all to the pick- and drill-resistant disc-style cylinder. You can also take advantage of the Transit Flex Frame bracket for plenty of convenient mounting options. The KryptoLok series 2 STD U-lock is 4 x 9-inches and has an anti-theft protection offer of $1,250.
I bought this because it secure both wheels and frame. It seems durable enough as it feels of nice construction and is pretty heavy without being a hindrance when biking to work. Unfortunately, my bike got stolen. The U lock still can be cut, and fairly easily evidently.
Bottom LineNo, I would not recommend this to a friend