Very disappointed. Ordered Oak - got ebony or black ash.  The backing isn't wood or even hardboard, but 250g/m2 screen printed card which doesn't stabilise the unit so it's not stable at all.  The shelves have bowed under the weight of books, but it's a bookcase and it bows because it's got books on it?
The shelves bow, fall off the shelving pins and the case wobbles - remedy, buying shelving brackets and hang the unit on wall with the brackets under each shelf.
DON'T BUY IT - WASTE OF MONEY - VERY DISAPPOINTED WAYFAIR'S products are usually very good.