Farmer in the Glen 10"x20.75" Waterproof Seedling Heat Mat for Hydroponics, Propogation and Cloning - Mat Only Seedling heat mat dimensions: 10 inches x 20.75 inches. Contents: 1 Farmer in the Glen seedling heat mat. Thermostat sold separately; Gently warms soil and root area 10-20 degrees Fahrenheit above the ambient room temperature to improve germination percentage and give seedlings the best chance at propagation. Fits under commonly-sized seedling trays. Increases the success of seedlings and cuttings; Lighting, watering, and planting guidelines conveniently printed on the mat; Constructed of multi-layer, waterproof material with durable heating wire inside the mat. Includes 6-foot power cord; Waterproof, flame retardant, PVC construction helps retain soil moisture for optimal seedling growth and safety from electrocution and fire. UL listed and approved;