The whole shelf turns on a 360-degree swivel plate, so a book at the back comes to the front with a push rather than being dug out - useful for a comic or manga collection stored spine-in. Each of the two tiers is split into four sections by dividers with baffles at the edges to stop books sliding off as it spins. The top holds 100 lbs and the unit 145 lbs in total. It measures 15.5 x 15.5 x 26 in with 12 in between shelves and weighs 22 lbs in natural engineered wood.