Super Sprouter? 4 Tray Seedling Heat Mat is designed for 4 standard 10 in x 20 in propagation trays placed side by side. The Super Sprouter? 4 Tray Seedling Heat Mat warms the rooting area approximately 10?20? F over ambient temperatures to improve the germination process. More consistent heating with fewer hot spots than other seedling heat mats on the market. Ed Hume seal of approval. 110 W. 5 ft 120 V power cord. Dimensions: 21 in x 48 in.