This mini-greenhouse is specially designed to increase germination success. It provides gentle warmth to the planting bed and controls humidity. The exceptionally tall dome, a full 6-1/2 inches high, is excellent for taller starts and cuttings. Two ventilation points at the top of the dome give better humidity control to foster optimum growth. The complete kit includes everything you need: a UL-listed waterproof heat mat that maintains an ideal temperature range for seed germination, clear dome with dual vent points, 11" x 22" watertight base tray and 72 cell seeding insert. Instructions included.