Ohuhu Seedling Heat Mat Heated Propagator 2 Pack, Plant Heating Mat Plant Warm Mat IP67 Waterproof, 21W Hydroponic Heating Pad Greenhouse Heating Pad for Seedling and Germination 10"x 20.75"Stable Heating SystemDesigned to increase the temperature of the rooting area 10 20 above the ambient air temperature, Ohuhu professional heat mat maintains temperatures around 20 30, perfect for indoor gardening plant growth and flower seed germination 5 Layer StructureOhuhu Seedling Heat Mat is made of heavy duty PVC material on the outside, with an alloy Nikrothal heating wire wrapped in a double insulated PET layer in the center for durability and