Listening to customers, they've made a good thing even better! These Hydrofarm seedling heat mats have been reengineered for better performance and greater durability. The new stronger heating wire, and thicker multilayer construction (50% thicker!) offer more uniform heating and the durability to withstand rugged greenhouse environments so they're tough enough for your home! Plus, the layers are heat-bonded (not glued!) to stay sealed year after year. By providing bottom heat (up to 20°F above ambient air temperature), you'll increase the germination rate and success of your seedlings and cuttings. Plus, each mat has a handy seed germination guide for many popular flowers and vegetables. 17W Mat, 9-inches x 19.5-inches, for (1) typical flats. Ship weight is 1 lb.