An open vent or soil stack terminal needs a cap that lets air pass freely while keeping rain, birds, and debris out. A louvre vent cap does this without restricting airflow. The 4-inch size fits a 4-inch vent or stack terminal. PVC-U louvre vent cap, sized for 4-inch (BS EN 1329 nominal equivalent). Wall thickness on this bore follows BS EN 1329 soil-pipe wall thickness for this bore, and the socket geometry follows BS EN 1329-1 so it seats correctly against other soil-and-waste PVC-U fittings on the same line.
