Heat Mat 20" x 20" (Jump Start)Bottom heat is one of the most important and effective ways to improve germination and rooting. The seedling heat mats have been re engineered for better performance and greater durability. The new, stronger heating wire and thicker multi layer construction offer more uniform heating and the durability to withstand rugged greenhouse environments. Increases success of seedlings and cuttings Warms root area 10 20F over ambient temperature to improve