Monument Racks require WOOD GLUE to assemble properly and to get the best quality out of your built racks. We recommend Gorilla brand wood glues. Our Monument Modular Rack System (MMRS) allows you to organize your painting area and get back to being productive with your painting and building time! All racks are made from Laser-grade MDF and assemble simply with just a little wood glue. Our TabLock system allows each rack to connect to others in almost any configuration to create the perfect organized area. Can be stacked vertically or horizontally for optimal layouts. The Shelf Rack - Two shelves with the ability to store just about anything! Lower shelf is 6" high, and the upper shelf is 4.5". Lower shelf can have one Brush Rack inserted. All Racks ship flat-packed. Finished dimensions of the Shelf Rack are - 11in x 11in x 6in (HxWxD) Go forth and build!