Product information 50 dl sized pi p large letter mailing postal boxes pricing in proportion save money on royal mail postage costs dl sized postal cardboard boxes extremely strong light weight and durable construction supplied flat packed for ease of transport storage quick seal single tape secure for extra strength box weight 25g ext dimensions approx 220mm x 110mm x 24mm internal dimensions approx 218mm x 108mm x 21mm these boxes are specially manufactured to fit through the