The Oxygen Pools OXY20A-BV-IG is a IG Ozonator for pools less than 20,000 gallons with a 2" manifold installs onto any type of filter without special tools. Using the existing pool pump, water is circulated through the generator which adds dynamic oxygen to the water as it circulates back to the pool. Standard manifold is 1.5 inch pvc. For 2 inch pvc installations, use a reducer bushing for best results.