The NEOPERL SPRING-FLO in 1.8 GPM. Same design as the original aerator that has remained unchanged since 1938. A plumber's favorite it has a slotted construction, large chamber with 3 screens. This female faucet aerator has a special Chicago thread design that is female 13/16 in. - 24. This thread is created by using a 349 adapter. This product is packaged in a tube of 6.