Aerator key material: The faucet aerator keys are made of plastic, strong and sturdy, which can effectively remove faucet aerators. Quantity and size: Faucet aerator sizes: 16.3 mm, 18.2 mm, 21.3 mm, 23.7 mm; 3 pieces for each size, 12 pieces in total, with 5 faucet aerator key removal wrench tools. Sufficient quantity to meet your needs. Compatible with select faucets: Please measure the diameter of the internal thread of your faucet before ordering to confirm fit. Note: Designed only for female-threaded faucets. Easy to use: These aerator keys allow you to easily unscrew and remove faucet aerators for cleaning or replacement, helping restore proper water flow. Aerator key function: Helps remove most standard faucet aerators. Measure carefully before purchasing to ensure compatibility.