Apollo Horticulture Premium Germination Seedling Seed Starter Kit w/ Humidity Dome, Digital Thermostat and Heat Mat 1 - Apollo Horticulture Premium Germination Seedling Seed Starter Kit Dimensions: Dome - 21.25" x 11" x 9.50" / Heat Mat - 9"x 20" / Thermostat: 5.25" x 3" x 1.5" 72-cell Seedling Inserts with 2 vent points for optimal airflow. Heat Mat Warms root area to 10 to 20F above room temperature to Improve root growth Thermostat provides constant optimum temperature between 68-108F / 20-42C depending on your specific crop. Package Includes: 1 - Dome Cover, Seedling Tray, Water Tray / 1 - Digital Thermostat / 1 - Heat Mat