Bottom heat is one of the most important and effective ways to improve germination and rooting. These new heavier duty heat mats will provide uniform heat for hundreds of seedlings or cuttings. Warms root area 10-20°F over ambient temperature to improve germination. Heat Mats are engineered for performance and durability. The strong heating wire and thick multi-layer construction offer uniform heating and the ability to withstand greenhouse environments. Mats feature waterproof connectors and can daisy chain up to 5 units together. Use with Hydrofarm's Digital Heat Mat Thermostat (41883-900).