The file 'Tap Aerator For 18mm Faucet 3D Printer Model' is (stl) file type, size is 6.4MB.
Thread radius is like 17.8mm so it fits 18mm faucets perfectly. You can use "thread seal tape" for the leakage which is from joints between faucet and the aerator.
Cheers
Aerator.stl | 12.6MB |