Yeah, it's 21U rack, the smaller one I managed to found with enough depth to Fit PowerEdge servers, and strong enough to hold the AEG UPS that's really heavy, but powers two main servers (700W minimum each) for about an hour. The rest is just placed on top of each other. When I find some free time, i'll consider getting a proper Rack Mount cases even for regular ATX boards, put them into rack, and make things look a little bit less messy.