It takes a very steady hand to fill lip balm tubes with out spilling everywhere. With this handy device, that is a thing of the past. The tray comes with 25 tubes which tightly fit into one side of the tray. Then flip it over and fill the tubes. The mold holds the tubes in place so they can't tip over and any "spilled" lip balm can be scraped off the top of the mold, with the provided scraper, once it has cooled. Note: The lip balm should be cooled to below 140° before pouring.