Sunlight Supply Dominator XXXL Air-Cooled Reflector &mdash; 6in. Dia. Vent Large 6in. dia. cooling vent Powder-coated galvanized steel body Swing Stop retention cable keeps glass from abruptly swinging down Captured thumb screws and closure mechanism for ease of use and excellent sealing Air-cooling flange has a bead ring to keep ducting securely in place