The tool less snap-in filler panels unique design allows them to snap into 19 in EIA/ECA-310-E compliant tapped or 3/8 in square hole mounting rails without modification - eliminates the need to stock two different types of panels|The patent pending design does not require field modification to fit a tapped hole - panel can be swapped back and forth between cabinets or racks with tapped or square holes as necessary|Specially designed clips - allows the panels to snap into mounting rails as thick as 0.187 in (typ. EIA rack) or as thin as 0.078 in (some server cabinets)|Ridges along the top and bottom rear edges of the panel - makes a seal without creating a tolerance build when using multiple filler panels|2 rack units|Tool less snap-In