Seedling Heat Mats for Seed Starting Propagation and Increase Seedling Heat Mat, Waterproof Heat Mat For Seed Starting, Seedling Heat Seedling Heat Mat 10 25 50CM Seedling Heat Mat Indoor Plants Germination Waterproof Amazon.com : Upgrade Version 4PK Seedling Heat Mat with ETL Listed,Warm. Jump Start MT10008 Seedling Heat Mat, 20 in L, 20 in W, 120 V Re engineered for better performance and greater durability. The new, stronger heating wire and thicker multi layer construction offer more uniform heating and the durability to withstand rugged greenhouse environments. Seedling heat mats offer versatility and portability for all your horticultural needs. The durable double layer construction is waterproof and makes them ideal for greenhouses, nurseries and hydroponic hobby gardens in need of maintaining a specific root zone temperature for valuable crops. Features: Increases success of seedlings and cuttings Warms root area 10 to 20 deg F over ambient temperature to improve germination Light, watering and planting information on mat Has waterproof construction 50% thicker construction