Cooling shroud is specifically designed for use with the Grundfos RediFlo 2 in wells 4″ in diameter or larger. The RediFlo 2 electrical submersible pump was designed to stay cool by the action of the water passing rapidly over the body of the stainless steel and Teflon pump. In 2″ diameter wells this is achieved automatically. In larger diameter wells the pump may overheat, causing permanent damage to the inner workings. The pump cooling shroud can help you avoid damage to your RediFlo 2 pump.