ohuhu seedling heat mat for plants, 10" x 20.75" met certified ip67 water resistant heating pad for indoor home gardening hydroponic germination, 21w durable seed starter warming mats ohuhu ohuhu waterproof seedling heat mat provides stable, even heating for better plant growth and flower germination. it is designed to increase the temperature of the rooting area 10°f to 20°f above the ambient air temperature to protect your plants and cuttings from the cold