This is an A4-sized organizing tray. It's convenient for organizing and sorting postcards, envelopes, and circulated documents. External dimensions: Approximately width 320 x depth 240 x height 105 mm Internal dimensions: Upper tier: Approximately width 310 x depth 230 x height 25 mm Lower tier: Approximately width 310 x depth 230 x height 45 mm There are two pen marks (see photos 3 and 4).