Technology RM41-506 4U rackmount Server case with six 5.25" Drive Bays, SST-RM41-506

it wasn't 19 inch. it is 17 inch by 17 inch square.

Don’t buy this unless you are using something that doesn’t kick off any heat. Getting any into the unit was a huge pain in the rear. It only had slots for 3 80mm fans. I ended up bolting 2 120mm fans into the drive bays. It ruins the look but the seller has a strict return policy that makes it pretty much not worth returning. For a rack mounted unit, the lack of airflow is appalling. 0/10 do not buy.

I have 2 of this chassis and its an absolute peach to build in as long as you don't need to put a relatively modern GPU in it... the depth of the chassis can't quite handle anything too much larger than a full ATX motherboard.You can put a cooler up to 148mm tall in it which gives you a lot of options. I run Thermalright coolers in both of mine and they fit with no issues just check height specs before buying a cooler.

I really like the design of this rackmount cabinet. It is roomy on the inside and very professional looking on the front panel. There is plenty of ventilation and it was easy to install the system board and drives.