Avery steel plated risers give you extra space between your letter trays. What you need are steel plated connectors to give you extra space. If you add four of these longer length risers in-between each tray, it will give you a clearance of 118mm. 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 metal risers are designed to fit Avery Letter Trays. You can also choose longer or shorter risers if you need more or less space.