The bookend racks adjust are on slides meant to accommodate a few or several books. This rack is made of quartersawn white oak with glued biscuit joints and a hot oil finish. I have never seen a book rack designed like this. I believe it to be original, one of a kind. Sizes and species of woods can be personalized. The stiles have mortise and tenon joints and the book ends slide on an oak rail. Size is 20"L by 7.5"W by 9.5"H.