SLUDGE15-4.0 Designed to be used on systems of 4 GPM or more, this sludge pump is perfect for cleaning out ponds and pits. The sludge pump with #4 tip features a 0 degree nozzle that is held in the suction cone creating a vacuum on the cone. It then draws a large volume of water through the 1.5'' tubing that is great for removing sludge from pits or any location. Features: -0 Degree nozzle that is held in the suction cone -Used on pressures washer that produce 4 GPM or more -Great for cleaning sludge from pits, ponds, etc.