The Pentair 510320 is a QuikSkim™ Skimmer Basket Silt Sock. Pentair QuikSkim® Venturi Powered Pool Skimmer is a vital part of your cleaning and circulation system. QuikSkim helps enhance the skimming efficiency and eliminates the need to use pump suction. QuikSkim allows the pump’s power to be dedicated to your pool’s drain for maximum debris removal. When used in conjunction with a VS pump, this process provides the most effective surface skimming available. This is a genuine Pentair product.