RockyMounts Compton U-Lock
Compton, the Compton Large's little brother. All of the same girth and security but in a more compact form. Weighing 4lbs and reaching 8inches in height, the Compton is great for taking your bike on the go through the city.
The 18mm stainless steel shackle is the largest and toughest available on market, just ask it. The shackle is CNC machined, from non-corrosive 304 stainless steel, which even in much smaller sections is very difficult to cut. Stainless steel is very hard on tools, even stainless-specific versions, and compromising it means serious tools, time, and desire. This design is ideal for expensive bikes that get locked up in the city for hours at a time. Or you could use it as the ultimate paper weight on a solid hardwood or stone desktop. Keep it away from the Ikea furniture. RockyMounts supplies three keys, so you have no excuse for being locked out, as it were. But seriously, if you live in the city and have a valued bike, regardless of what is actually worth, you need to invest in the RockyMounts Compton U-Lock.