Very easy to assemble if you've used the two-sided plastic 'anchors' at each level the rack , drawer, or top needs, it's a breeze. (just need a rubber mallet).  The tires are rubber (from the smell), so I did put duct tape around them (latex and rubber cause discoloration on luxury vinyl tiles and vinyl flooring in general), and they still roll well .  The unit is sturdy, and makes a perfect cart for my low-cal naturally sweetened beverages, to reload the fridge.