Google Customer Reviews 
U Locks are the the strongest, simplest bike lock. Easy to use & easy to mount on your frame so that you never leave home without it.
The famous U-Lock will never let you down. The reason these are so popular are that you will find them super easy to use. Their simple shape makes them probably the fastest way to secure your bike. And this has been a huge factor in their popularity with bike couriers & messengers.
Not only will you find a shackle U-Lock easy to use & super fast, it’s also hard to break. The usual way to steal a bike that is well locked is to cut the lock. The benefit of the U-Lock is how hard it is to bend. Requiring two cuts rather than one. Twice as secure!
