Master Lock U Lock, 6-1/8 in. Wide – Link

Amazon has this marked down to $9.88.

• Heavy duty U-lock with protective vinyl coating to prevent scratching
• Best used to secure bicycles
• Bike lock has a double locking shackle for pry resistance
• Hardened steel body to resist cutting, sawing, and prying
• 6-1/8 (16 cm) wide, 1/2 in. diameter shackle with 8 in. (20 cm) length and 4 in. (10 cm) width; carrier bracket and two keys included
• Affordable U-Lock Protection
• Disc key for additional anti-pick protection