Protect your bike with Giant's SureLock Protector 2 STD U-Lock. It boasts a heat-treated, hardened-steel shackle that's a half-inch thick and 11.5 inches long, as well as a pick and drill-resistant keyed lock. The extra-length lets you lock your bike to extra-thick posts or include wheels in one securely locked package. This tough lock includes five laser-cut keys, is vinyl coated so it won't scratch your bike, and comes with a handy carrying bracket that fits almost any frame so you'll never have to leave your lock behind.

- New hardened deadbolt anti-rotation design - Includes 2 Stainless steel keys with an ergonomic design to reduce the amount of torque, and keep them from bending or breaking - Includes side mount, snap-in bracket - Disc-style cylinder with center keyway - Key Safe Program - Product dimensions: 4” x 10” (10.2cm x 25.4cm) - Product weight: 2.25 lbs

- New hardened deadbolt anti-rotation design - Includes 2 stainless steel keys with an ergonomic design to reduce the amount of torque, and keep them from bending or breaking - Includes side mount, snap-in bracket - Disc-style cylinder with center keyway - Key Safe Program - Product dimensions: 4” x 8” (10.2cm x 20.3cm) - Product weight: 2.05 lbs

Kryptonite's Keeper 12 Long Shackle U-Lock is like a tough nut: you just can't crack it. Thanks to the 12mm hardened steel shackle that resists cutting and leverage attacks, you get peace of mind while you run into the grocery store or lock up outside the coffee shop. The shackle connects to the disc-style cylinder for exceptional security, and it all sits in the click-style transportation bracket so it stays stable during transport. To top it all off, you get a reinforced collar over the keyway for added protection, not to mention Kryptonite's Anti-Theft Protection offer. The lock measures 4 x 11.5-inches for plenty of locking clearance.