If your after the ultimate in security and want to leave your bike at the train station but don't want to carry a big and bulky U-Lock then look no further than the Onguard Link Plate Lock. 

This unique lock combines U-lock security with the ease of use and versatility of a cable lock. Remarkably compact the K-9 is constructed of hardened steel plates and features steel ball Click-Combo-Gear System that’s user settable with 10,000 possible variations. Once unfolded, the K-9 has the length to secure frames and wheels to a rack or other solid object. Included mounting bracket mounts to most bicycle tubes for easy transport.