Document shredders are important pieces of basic office equipment. With these you reliably destroy confidential documents. The low-priced models include narrow forms with a collection bin. They shred up to five sheets vertically at a time. Higher-quality versions are those that shred forms into small particles no more than four centimetres long. Machines from Fellowes break up an A4 page into 2,000 tiny pieces. They are particularly safe. It is almost impossible to put the document back together again.