Hydrofarm JSEF55 Smart Float Grow Tray with Plugs, 21" x 11" x 2.5" Not sold in ID,OR Smart Float provides an ideal air-to-water ratio Perfect for starting seeds or cuttings All natural Ready-Gro plugs and reusable insert keeps your garden "green" Use with Hydrofarm heat matts and domes for more robust growth Plug refills available to ensure you never have to buy more equipment