The 45" x 25.5" Cloning Rack Tray by Microclone fits into standard chrome and steel racks chosen by growers for their efficient use of space and light. Many retail stores, plant shops, web postings, and magazine articles reveal how popular these racks are for cloning. The trays line up neatly in rows of as many as four per shelf and many rack systems have five or six shelves and low profile lighting. Fluorescent fixtures, especially T5s, fit naturally in the plant shelves. Clone growers put their propagation trays under the lights like a baker cooling trays of cookies.