These Louvered Ventilators are constructed of impact resistant injection molded ABS and are designed to be used in conjunction with a collector box to facilitate air intake and exhaust. Interchangeable with Attwood vent #1494. Installs with four #8 FH fasteners (not included). Avoid contact with acetone or strong solvents. Dimensions: 2-5/8" x 17-1/2" L x 2-5/8" H x 7/16" D