This attractive, dome-shaped aerator filter protects pumps from any debris in the water. The fully curved and perforated surface allows more efficient flow than other molded filters. The filter top simply turns and locks tight onto the base that fits underneath the thru-hull flange. The two-piece design allows for easy cleaning and simple installation with no fasteners. Filter mounts onto aerator pump snout or thru-hull fitting. This filter can also be used as a screen for overflow drains. Prevents drains from clogging. Fits on standard thru-hulls or pump intakes. Easy twist-off cleaning. Mounts Behind Standard Thru-Hulls. Fits 3/4" thru.