The MONT 4 ft. extension kit is specifically designed for the MONT - Mojave Edition line of greenhouses. The idea is simple, as your gardening greenhouse needs grow so can your greenhouse. The 4 ft. extension kit allows for the expansion of your existing greenhouse. 4 ft. extension kit includes: 4 ft. complete middle section framing of the greenhouse, excluding front and back walls, 4 bronze light deflecting panels for roof and 4 clear wall panels, 4 ft. irrigation extension with 1 sprinkler head and 4 ft. work bench extension kit. When ordering your extension kit make sure that the color matches your existing greenhouse. This 1 is designed specifically for Black frames and will work with the following greenhouses: MONT-8-MOJAVE-BK, MONT-12-MOJAVE-BK, MONT-16-MOJAVE-BK, MONT-20-MOJAVE-BK, MONT-24-MOJAVE-BK. Material: Aluminum.