Romanoff Plastic Stowaway Letter Tray, 3", Green. Our 3'' Stowaway Letter Box is an ideal way to protect and store your stationery, or important documents you need to save safely. Choose from the number of great colors we offer, and stock them atop each other to save space! 13 x 10.5 x 3 in, Fits Paper: 8.5 x 11in. Bundle of 3 Boxes.