Epic 16-Cell Trays are rigid, yet flexible and practically unbreakable to last the rest of your life. Proudly made in the USA from recycled, UV-treated, and BPA-free Engineered for Perfect Plant Growth Each individual cell in our Epic 16-Cell Trays features 4 internal ribs to prevent root spiraling.  The bottoms of each cell are also open providing air pruning at the lower end of each cell.   Convenient and Flexible 8 Epic 16-Cell Trays are designed to fit into a 1" 1020 Universal Bottom Tray, mimicking a classic 128-cell tray. They are also compatible with our Epic 4-Cell Humidity Domes. This design gives you the convenience of having all of your seedlings in one tray.