Single Wall Packing Cardboard Boxes 12"x9"x4". Perfect for small items, A4 documents, leaflets etc. Most commonly used in the printer industry as well as by on-line sellers for sending small products (eg nutritional products etc). These have an A4 size base (12x9") and are 4" high. These boxes are compliant with the new royal mail 'small parcel' guidelines effective 1 April 2013, and subsequently updated in October 2014, hence carry a reduced rate of postage in the royal mail system, as they qualify as small parcels.