Alera ALESW504824BL 48" x 24" x 72" NSF Certified Heavy Duty 4-Tier Wire Shelving Unit - Black | Commercial Kitchen, Garage Storage, Warehouse Organization

An excellent multi-purpose shelving unit, this set stood up to my daughter and I jumping on them with no problem. Looking around at other websites, these shelves have a max capacity of 1,000 lb. per shelf on the 24" x 36" version and 1,250 lb. per shelf on the 18" x 36" version.I currently use them to hold 5 gallon jugs of water and 50 lb. buckets of salt for my aquarium as well as some tool boxes. I've personally never had more than about 250 lb. or so per shelf so I'm not sure how well they will do at maximum capacity.I currently have them in my storage closet but they would also work great for dry garages, commercial kitchens, or shops. The stand is not super heavy, the total package weighs about 64 lbs.The shelves are extremely easy to put together and normally require no type of tools unless you are strapping them to the wall which I haven't done. I did use a hammer to tap in the caps on top of the poles since I used the two 2 shelf configuration. All hardware is well made and seems very durable.The poles have notches about every 2 inches so you can set the shelves to whatever height best fits your needs. If you separate them evenly, there is about 18 inches between each shelf minus the small overhang on the bottom of the shelf. If you don't need nearly that much space between them they offer individual pieces you can buy separately so you can always add a couple extra shelves to it (I'm not sure the total weight limit on the poles if doing this.)The edges of the rack have a very nice lip that hangs down around it which can be used with hooks to hang kitchenware or tools from or with wire-ties to organize wiring if using it for a server or music rack or some other type of electronics.I have not used castors with mine so I can't comment on that part. The overall look is very clean. For an industrial grade item, this thing looks good.Overall, I think this rack is a great value. It is nicer than some shelving I've seen for 3 to 4 times the price and I intend to buy a couple more in the future.