Super Sprouter? AirMax? Tray Inserts help provide outstanding drainage and aeration to clones grown in Grodan Stonewool A-OK Starter Plugs?. These mesh tray inserts are designed to allow high levels of oxygen to enter the root zone in your clone trays. More oxygen at the roots can help maximize root growth and help minimize damping-off in young clones and seedlings. By elevating plants above the propagation tray?s bottom surface, the AirMax? allows excess water to run off and holds plants above standing water. This helps to avoid oversaturated roots and promote proper drainage and airflow. Its low profile provides clear visibility to root development and unrestricted access to cuttings for proper care and monitoring, without disturbing delicate plants.