For use with q connect letter trays these steel risers allow you to stack trays providing additional space saving storage on your desk or work space the risers insert easily onto each corner of your letter tray for a 123mm clearance between trays this pack contains 4 steel risers features pack of 4 clearance height 123mm letter tray risers for use with q connect trays made from steel for durability provide additional space saving storage fit easily to four corners of tray