Review on ManLee 20 Set Water Saving Faucet Aerator Key Insert Replacement for M16.5 18.5 21.5 24 Cache Tap Aerators - Flow Restrictor for Sinks by Chris Munns

These aerators are available in different sizes. Unfortunately, none of them fit the Delta bathroom faucet. The aerator itself appears to be 15.5mm but comes in a threaded piece. 16.5 with its own thread is too small. the next size no longer wants to use the wrong size or thread that is too big. Delta seems difficult to replace, replacements are not available in HD or Lowes. For me there is no more delta. I'm giving that 3 stars because I don't mention it's not Delta friendly. Maybe something else fits. By the way, this type of internal fan is called a cache. Stupid.