Brand leader General Hydroponics invented the best in bio starter plugs available. Rapid Rooter plugs are all natural soil-less organic grow plugs made of composted tree bark and organic materials. Teaming with beneficial microbes, Rapid Rooter plugs give seeds and cuttings the best start available and propogation rates that are second to none. These plugs are perfect for seedlings or cuttings. Transplant plugs in soil or soil-less hydrogardening applications. 50 cell tray with plugs-