PVC pump shrouds are installed over the body of the pump and motor so that the water flow past the motor is sufficient to achieve adequite cooling of the motor. Easy to fit and definitely required if you are installing the submersible pump in a well or bore with a diameter of 150mm or greater. This model fits the 40mm pump outlet range. The price is for the shroud only as each installation requires different fittings so the fittings are extra.