Close the lid or close the bin, the Stack-and-Shred starts doing its job as soon as both are in a safe position. To avoid jams, the feeder automatically inserts a few sheets of paper at a time into the shredder, which is roughly centered about the bin. Paper as thick as 20 pounds also is OK for the auto bin, and can be folded in half if it's longer than 8.5 x 11 inches. Materials to avoid include edge-bound booklets, unopened mail, magazines, glossy or laminated documents. The device worked more quietly than we expected; it's rated at 60db. And at 12 x 17 x 17 inches, it could easily fit under a desk.