The object is the main enclosure for a personal computer, apparently of Soviet manufacture. There is a permanently attached power cord with lugs rather than a connector. There is a detachable monitor cord. There are four connectors on the back, labeled in Cyrillic; one for the monitor cable, one for the keyboard cable, and two unknown. There is a push-on push-off switch on the front, presumably for power.
Hand-written in red permanent marker on top back edge
overall: 4 3/8 in x 18 in x 19 in; overall: 23 1/2 in; overall: 330 in