Some parts of my collection fit into a 19" rack. No wonder,
this was (is?) industry standard. The rack itself is from
DEC (Digital Equipment Corp.) and hosted a PDP-11/34 years ago.
The rack contains (from top to bottom):
The first picture shows the Sun 3/E from behind and the second one
shows (beside a 12 slot chassis) the mess of cables in the 19" rack.