Paper shredders are broadly categorized by the type of shreds they produce; Strip-cut or Cross- cut models. Strip-cut shredders produce long strips of a preset width,1/8" and 1/4" being the most common. Cross-cut shredders have specially milled cutting cylinders to achieve a dual cutting action that produces particles of uniform length and width. The Cross-cut category is further broken down into High Security and Commercial security levels. A High Security shredder produces tiny particles that meet strict Department of Defense (DoD) requirements for the terminal destruction of top secret documents.