2 Tier Cube Carousel
This square shelving column turns in a full 360 degree rotation, enabling easy access to all four sides of storage. The Cube Carousel holds almost twice as many binders per level as a traditional bookcase shelf with the same width. Each tier is divided into four quadrants and each quadrant fits four Standard 3" Bindertek Binders, sixteen binders total per tier.
More information: http://www.bindertek.com/2-tier-cube-carousel.html