This tray is optimized to eliminate standing water in your vertical system. The Botanicare Mobile Rack Tray is crafted from heavy-duty ABS plastic with long-term performance in mind. It provides a level planting surface, while directing run-off to a central drain with the built-in 1.5? offset. This design helps prevent excess liquid in your setup. The Mobile Rack Tray is tailored for the Spacesaver Widespan GROW system and is also compatible with other manufacturers? systems.