Completely sealed featuring hinged glass and double gasket for an air-tight seal. Includes tempered glass, built-in socket and 15 ft lamp cord. Highly reflective aluminum interior for excellent output and uniformity. Swing Stop™ retention cable keeps glass from abruptly swinging down. Captured thumb screws & closure mechanism for ease of use and excellent sealing. Air-cooling flanges have a bead ring to keep ducting securely in place. Powder-coated galvanized steel housing. Patent No.: D543652, D570295, D613900, D698628. Overall Dimensions: 23.8L x 22.2W x 7.4H Glass Frame Dimensions: 18.7L x 22.2W