Is your letter tray piled high with papers? Struggling to fit much more in? What you need are these plastic connectors to give you extra space. If you add four of these risers in-between each tray, it will give you a clearance of 75mm. You will be able to store additional items in your plastic trays without them overflowing. There's no need to worry about losing papers down the back of your desk. These plastic risers are designed to fit all Avery Stacking Trays. You can also choose longer risers if you need more space.