These posts are only 1/2" diameter, rather than 3/4" or 1" (as other units I've purchased -- see similar 4-shelf Hyper Tough brand unit available here). Also, the posts are in four segments, and the segments just press-fit together, rather than screwing together. So, overall, it makes the unit a little flimsy. However, it works for my purposes, and I have some heavy items on it -- I'm just super careful whenever I move the unit. Also, as another reviewer noted, the height of the assembled unit is significantly taller than the drawing. With the casters (wheels), the full unit is ~63" high. So for mine, I just used three of the four post sections, and was still able to use all five shelves. So, bottom line, it's an okay shelving unit, but if I need something similar in the future, I'll probably buy a different one.