OnGuard Bulldog DT X2 Double Bolt locking Mechanism provides added strength and high pull resistance by locking tight to 2 sides of the bar 13mm Hardened steel shackle Includes a multi-position mounting bracket Anti-theft Protection offer Pick, pull, and drill resistant Z-key Cylinder featuring BumpBlok 5 Laser Cut Keys, 1 with a LED micro-light Protective coatings on the cross bar and shackle