Around 12 years ago I helped design and set up a 48-drive, 9U, ~120TB NAS in the Chenbro RM91250 chassis (still going strong! but plenty of drive failures along the way...). This looks like it's probably the 24-drive/4U entry in the same line (or similar). IIRC the fans were very noisy in their original hot-swappable mounts but replacing them with fixed (screw) mounts made a big difference. I can't tell from the picture if this has hot-swappable fans, though - I think I remember ours having purple plastic hardware.