Material: these aerator keys are made of durable ABS, non-toxic, odorless, and safe to use, convenient to remove with a long service life 5 Sizes of keys: these faucet aerator keys have 5 different sizes, M16.5, M18.5, M21.54, M22.5 and M24, a variety of different sizes meet your different needs, there is always a size that suits you, there are two for each size for you to replace; Note: please measure carefully before buying Practical and functional: the faucet aerator tool set to replace or clean the blocked aerators, effectively fixes the low flow faucet and gives you smooth flow again Wide application: with wide compatibility, the faucet aerator keys are fit for aerator with serration and screw thread, and come with 5 pieces to meet your need for use and replacement Easy to use: cache aerator keys can remove most aerator, replace or clean clogged air ducts with our aerator removal key to fix low flow faucets, the ABS wrench prevents scratches or damage during aerator removal or installation, bringing you a relaxing life