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OnGuard PitBull Medium U-Lock

This product is no longer available, but don't go just yet.


  • Burly 14mm (0.55 in.) hardened steel shackle resists cutting, prying and jacking; rubber-coated shackle and crossbar help protect your bike's finish
  • X4P Quattro locking mechanism secures the shackle to the crossbar in 4 places, maximizing strength to resist pulling, jacking, prying and twisting
  • Z-Cylinder tumbler is bump-proof and resists picking, pulling or drilling
  • Rounded design and centered keyhole eliminate pry points; all-metal end caps protect against drops and hits while the auto-closing keyhole cover protects lock internals
  • Comes with 5 laser-cut keys, 1 of which has an integrated LED light; mounting bracket Included
  • OnGuard rates the PitBull Medium U-lock as an 80 out of 100 on their 100-point security rating system, where higher-rated locks offer increased security


View all OnGuard U-Locks

REI membership


Best Use Bike Commuting & Touring
Lock Style U-lock
Lock Type Key Lock
Lock Thickness (mm) 14 millimeters
Material(s) Hardened steel
Dimensions 6.9 x 3.55 inches
Mounting Frame
Weight 3 lbs. 1 oz.

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