Size: the outer diameter of the top is 20.9 mm/ 0.82 inch, that of the bottom is 18 mm/ 0.71 inch, universal fit most standard 22 mm, 24 mm faucet Function: ease the impact of water, and prevent water from splashing by generating lots of bubbles, the strainer inside can filter out most impuritiesStandard Package includes: comes with 12 pieces of faucet aerators in a pack, enough for your different needs, such as home, hotel, faucet fittings of communal facilities use and replace Application: suitable for the installation and replacement of faucet fittings at homes, hotels, public facilities and other places, which is conducive to water saving and filtering water Quality material: the faucet aerator is made of ABS plastic, durable for long lasting use and easy to install, the fine mesh has good filtering effect, which can keep stable constant water flow, no water splashing