Super Sprouter® 50 cell Root Star® tray insert is custom-designed to properly support the Perfect Plugs™ while directing the roots down through its star pattern design. The patent-pending design also allows partial root pruning to strengthen the directed roots. Fits snugly into Super Sprouter® 10 x 20 in propagation trays. This Root Star® insert is very durable at 2 mil thickness. Individually marked with a UPC label for retail use.