These cabinets are a grade lower than the stuff you get at big box stores.  The backing if these cabinets is an insert that is about as thick as two index cards- or less than half of normal cardboard. It is held completely together with casters. If you are putting more than one up next to one another you’ll find no two can be assembled alike. They aren’t square. And out of the 3 we ordered none had a complete set of hardware. 

Also note the weight limits. Basically 30lbs per shelf. As you approach half that these cabinets get wobbly. 

We removed ours. Had to throw away and get real cabinets. These are only good for holding towels or other light items. Even then I don’t personally trust them