19-inch plates serve several purposes. We offer connector plates, for example, which you can use to mount chassis connectors.. They accommodate D-size XLR jack plug and Speakon chassis connectors We also offer closed blind plates that allow you to fill up empty spaces and ventilation plates that discharge your equipment's heat. This category also includes 19-inch plates with brushes that allow you to keep your cabling dust-free, as well as 19-inch cover plates with transparent covers and locks to prevent others from altering the settings on your gear. That also applies to crossovers and Speaker Management Systems.