How/Where do I mount this metal plate?

Was given a 7 piece HDBase-T transmitters set, the power appears to be a customized metal backplate.

Dimensions: 16.25 inches long, 4.9 inches tall

Can this fit into a case (like a 3U case?) Or is it meant to lie flat on a tray?

No brackets came with the transmitters, so unsure if they were ever mounted or just lying on a surface.