A Clean, Contemporary, Louver Designed Vent. Corrosion-Resistant Abs Plastic. For 3 Or 4"" I.D. Ventilation Systems. Install With #8 Screws. Sized For Installation Even On Highly Contoured Decks. Size 17-9/16""L X 2-3/4""H X 11/16""W. Installation Hole Size 2 X 15-3/8. Color: White Packaging: Bulk Color: White Packaging: Bulk Part Number(s): ATT 1494F1 ATT-1494F1 ATT_1494F1 ATT1494F1 23-1494F1 " Size 17-9/16"L x 2-3/4"H x 11/16"W White