Exclusive! Holds moisture and warmth for germination. 2" tall. Fits standard 10 x 20" flats and trays to create a warm, humid environment that is ideal for germinating seeds. Compatibility: Rests on all flats and trays except Hard Plastic Perma-Nest, Jumbo Plug Flats, Mesh Trays, and unsupported Pro-Trays. NOTE: Domes may appear different than in photo.