The Lambro 4-In. ABS Plastic Roof Exhaust Vent is ideal for venting through the roof. It features a damper and removable hinged screen (screen should be removed for clothes dryer applications) that prevents outside elements and air from entering the vent. The damper seals the vent opening when the clothes dryer or bath fan is not running because no exhaust air exits the vent. When the clothes dryer or bath fan operates, the exhaust air pressure pushes the damper to let the exhaust air escape from the vent. Warning: use only on shingled roof installations. The exhaust vent is for new and replacement installations. The vent frame comes with 6 predrilled nail holes to secure the vent to the roof. When using the vent to exhaust a clothes dryer, check the inside of the vent regularly to prevent lint buildup. The vent's manufacturing material is ABS (Acrylonitrile Butadiene Styrene) with a UV additive to prevent premature fading caused by sunlight. It would be best to prep the vent before painting it; plastic paint is recommended to effectively paint the plastic vent. Make sure to check local building codes before installation.