Soler and Palau WC-4 Worm Clamp 4-Inch for Air Duct, Small S&P is the world's leading producer of air movement products. S&P manufactures and supplies fans, dampers, louvers and recovery ventilators Used in various industries including residential, commercial, industrial and institutional buildings. S&P is the world's leading producer of air movement products. Used in various industries including residential, commercial, industrial and institutional buildings.