The Ken-Bar High Tunnel Roof Vent installs directly into the film covering of high tunnels with no additional framing required. Its unique clamshell design prevents water intrusion while providing 2.5 ft of ventilation space. Weighing only 8.5 lbs., the Roof Vent uses standard wire lock and channel to attach securely to greenhouse poly film. Flexible U.V. stabilized polycarbonate provides un-matched clarity for maximum light transmission, while the aluminum construction ensures long service life. Roof vent helps create chimney effect drawing in air and increasing air flow upward through trellised plants. Vent utilizes a heat activated automatic vent opener that can be adjusted to begin venting between 65°-75°F. Pair with Ken-Bar’s High Tunnel End-Wall Vents for a complete supplemental ventilation solution. Overall dimensions: 36.5” x 20.5” x 4” (Interior opening 30.5” x 12”).