Grodan A-OK Starter Plugs are designed for starting seedlings and rooting stem cuttings. The finely woven stone wool in the Starter Plug provides the perfect environment for young roots. Square plugs form a sheet that fits standard 10 by 20 trays, with tapered bottoms that support transplanting and promote uniform root development. Grodan plugs have excellent uniformity, strength and shape that provides the perfect basis for optimum germination and uniform seedling results. The uniformity and reliability of Grodan plugs provide a solid basis for automatic or manual processing, uniform germination and a crop that can be transplanted successfully. Grodan plugs have a uniform density, firmness and fibrous structure. This means that distribution of water, nutrients and pH-value is also uniform, which has a beneficial effect on germination results.