RECTGV1824 EZ HERITAGE CREAM EZ/59 18X24 VNYL GABLE VENT | 18" x 24" Rectangular Gable Vent - The 2-piece system is fully compatible with all siding profiles, colors, and types. Simply install the base when installing the siding, then snap on the cover later. Rectangular base makes siding cuts easier. Adjustable 5/8" to 1-1/4" for use with all siding styles. Each gable vent includes screen protection to keep pests out. Manufactured with ultraviolet-stabilized color, minimizing the effects of exposure to the elements. Rich textured appearance. Outside dimensions: 18" x 24". Ventilated opening dimensions: 16" x 20". - Surface Dimensions: 18" x 24", Shape: Rectangular, Material: Vinyl, Net Free Area: 99.4 sq in.