Drip channel drains water to the front of the siding to eliminate wood rot. Wide trim ring, removable template, large flange and level lines. Injection-molded UV-resistant polypropylene for impact. Molded in screen prevents insects and bees from nesting in gable vent. Molded in screen cannot become unglued. Deep wood grain finish enhances appearance for a real wood look. Weeping holes prevent condensation or moisture from remaining trapped. Suitable for use with vinyl or aluminum siding, shake, stucco or brick. 44 sq-in of net-free area for 12 in x 18 in and 18 in x 24 in. 74 sq-in of net-free area for 22 in x 28 in. Rough cut opening is 12-1/2 in x 18-1/4 in.