Master Lock - Hidden Shackle Locks Keyed Alike #6271KA-2 This lock is also available with the BumpStop Technology. Search 6271NKA in Amazon's search window. "Bolt Cutter Tough" fully shielded hardened steel shackle offers impossible to cut and pry resistance features. Hardened diecast steel body is strong, durable and resists corrosion. 6-pin cylinder for maximum pick resistance. Removable cylinder for replacement or repinning. See image for reference - Shackle Dimensions - A: 3/8in (10mm) B: 19/32in (15mm) C: 1-23/32in (44mm)