not a great bookshelf, poor construction, dowels don't fit the holes as the holes are far too big making them pointless and is a real struggle to fit as they keep falling out and you have to take your time and glue them all in. The countersunk holes for the allan  bolts are too deep and you cant  use the provided allan key and have to source another one with a long handle and a t bar. after all that , the unit just doesn't look that good with varying dimensional gaps with 1-3 mm. Definitely better products out there