The Hot House mini greenhouse growing system offers increased growing success by providing gentle warmth to the planting bed and by controlling humidity under the large dome. The dome offers two ventilation points on its top. The growing system includes UL-listed waterproof heat mat, six-inch-tall humidity dome, 11-inch by 22-inch watertight base tray, Jump Start 81 pellet greenhouse, and instructions with growing tips. Start with our 2" dome with vents, move up to the 7" sturdy dome with adjustable top vents for growing bigger and taller starts. Comes with all the basics including the heated mat to ensure your success! The Hot House Plus comes with the Jump Start Coco 81 Pellet seedling tray.