Gorilla Grow Tent 1' Extension Lite Line Size 4'x8'This 1 ft. height extension kit gives you the ability to increase your growing height from 67 to 77. Benefits to raising the roof include: 1. Significant Yield Increase More usable growing height allows you to cultivate larger plants. Larger plants produce larger quantities of fruits and flowers. 2. Getting the party started. 3. Stable, Ideal Temperature Around Plants Heat rises. With the additional height this kit provides, your heat will stay up by