These little L-Brackets are designed to hold Dollar Tree Foamboard (Adams RediBoard) to create a cheap/easy enclosure for your 3d printerSlide the foamboard into the slots. The top cover for the printer can just be sat on top of the 4 walls. You can either print 8 brackets, 4 for top and bottom, or just use 4 on the top/bottom. Cut appropriate holes for your cables, and maybe a peep hole to view your print and/or LCD screen.