If you need a lock to keep your bike secure, but don't want to empty your wallet in the process, check out the Standard U-Lock from Avenir. The 4 x 9 inch 'U' is 11mm thick to withstand bolt cutters and it comes with a mounting bracket and a spare key too. Only available at select stores.
4 x 9 inches
11mm thick shackle
Includes mounting bracket and spare key