This indoor 20" x 10" mat is perfect for the traditional seed starter trays as well as individual plant propagation cuttings. Keeping the roots 10 to 20 degrees over ambient temperature are perfect for seeds & propagation starting. Designed with waterproof construction so it is safe for indoor plantings. The new stronger heating wire and thicker multi-layer construction will offer more uniform heating and durability to withstand rugged greenhouse environments too.