The difference between a paper shredder that makes quick work of your private paper trail, versus one that makes you regret taking the time and effort, usually comes down to a handful of key features. Runtime refers to how long a shredder can operate continuously before it overheats and needs to cool down for awhile—basically how long you can keep feeding paper before the shredder shudders as if proclaiming “Ya wanna let me breath for a minute?” Most shredders handle paper, staples, and paper clips, but not all can handle thicker materials like credit cards or CDs.