Size: 91B. 3 7/8″ high x 2 1/2″ wide x 1 3/8″ deepx 1/2″ shackle diameter. Machined entirely out of a solid block of stainless steel with exotic maraged steel shackle. Cylinder protected against drilling with spinner disk and protected against pulling with special extra strength carriage which requires keys to be longer than average.Patent #’s 3882699 4918950.