EIA-310-D – Defines the official 19-inch rack width, height unit (U) of 1. A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. 6 mm), allowing different hardware from various. The 19 inch chassis (482. Technically, this 19-inch measurement refers to the width of the front panel of the mountable module that slides into the rack, while the actual server chassis width needs to be less. The InoNet 19 inch rack chassis are dimensioned according to height units (U). in data centres, to mount several computers or servers. When designing and choosing 19-inch cabinets, it is important to consider 19U rack dimensions: height, width, and depth.