The Insert Tray (Case of 28) Rigid, Reusable 50-Cell Propagation Insert The Insert Tray is a heavy-duty propagation insert engineered for repeat use and long-term durability. Molded from thick, high-density plastic, it offers significantly more rigidity than standard 50-cell trays, maintaining its shape through repeated irrigation cycles, handling, and sanitation. Designed to fit any standard 10×20 flat, the Insert Tray delivers uniform spacing and consistent plug support for efficient, repeatable propagation. Its precision-molded cells securely hold Coco Coins, peat plugs, or 1.5-inch rockwool cubes, allowing growers to run their preferred media while benefiting from a more robust tray system.