Growers Supply Company GSHM 9-by-19-1/2-Inch Small Seedling Heat Mat (Discontinued by Manufacturer)
This seedling heat mat is 9-inch by 19-1/2-inch (Model # GSHM) is designed to fit under one of our Perma-Nest 22-inch by 11-inch plant trays (GW2211, GT2211, GS2211) or one standard seed flat. Warms the soil in the tray 10-20 degrees Fahrenheit above the room temperature, helping seeds to germinate and grow faster.