The Abus Ultra 410 Mini U-Lock might be small in stature, but it packs a punch against thieves and lock picks. Constructed with a 12-millimeter thick temper hardened steel shackle, the lock is burly enough for cities, but compact enough to toss in your pack when you're heading to work or class. It uses a patented double-layer lock cylinder with special wafers and additional decoy cuttings that protect against even the savviest of lock picks, and a double deadbolt heat that keeps things secure against torsional attacks. To top that off, the lock can easily be carried on your frame with the included SH-34 bracket, keeping the lock within your front triangle, or if space permits, inside of your rear triangle for safe keeping on your journey.