(4) Hydroponic 19006 17W Seed Start Seedling Propogation Heat Mats | 8.87 x 19.5" 8.87" x 19.5" Mat - Fits under one common seed flat Gently warms root area to improve germination Increases success of seedlings and cuttings Warms root area 10-20F over ambient temperature to improve germination Light, watering and planting instructions on mat