This bookshelf is called the Hold On Tight, designed by Colleen & Eric. It is a cube with a an oversized wing-nut that you can loosen and slide on a track to make room for more books. Offered in Beech, Walnut and Oak. Water based stain and all natural Shellac finish.
Aluminum cube and wingnut powdercoated. Just contact them for the pricing.

[via LikeCool]