Hi Milo, Thank you for your question. The faucets that take the RP52216 aerator were part of a running change that switched the aerator being used on the faucet. The RP52216 ships with both aerators which have a flow rate of 1.5 gpm, but have different thread patterns on the aerator. We do offer 1.0 gpm aerators that will work in place of the RP52216. If you have the shorter version of the aerator that has an o-ring around it then RP63886 will work. If you have the taller aerator with a gasket on top of it then the RP72730 will be the 1.0 gpm version.