Mine is five blacklight fixtures from Home Depot screwed to the underside of a shelf in an IKEA shelving unit (IVAR, the deep one, not the bookshelf sized one). They all plug into a power strip which I then connect to a Gra-Lab digital timer. Total cost, including the shelving unit, was about $200. With this setup I can do up to 12x20 or 14x17. I probably could do 16x20 but I've never tried as I don't have anything that big. The lights are about 2" from the surface of the glass of my contact printing frame.