【Filter Replacement Interval】For consistent water purification , we recommend replacing the shower head filter replacement every 3 to 4 months or after filtering 12000 gallons of water 【Powerful Filtration Feature】Practical shower head replacement filter consists of 50% KDF-55 media , 50% calcium sulfite balls , paired with activated carbon , effectively removing bad substances , remaining chlorine , and heavy metals from the water . It helps relieve dry , itchy skin and ensures a clean , safe bathing experience 【Ideal Fit Design】Safe shower head filter replacement cartridge measures approximately 10 x 2.5 cm/3.94 x 0.98 in and fits most filtered handheld shower heads . Please verify the size before use 【No Tool Installation】The filtered shower head replacement filter is quick and easy to replace , simply open the shower head housing , retrieve the old filter , and insert the new one . Ensure the O ring is properly seated during installation to avoid leaks 【Gentle on Skin and Hair】Efficient showerhead filter replacement improves hard water quality , helping skin and hair lock in water while reducing dryness , redness , and discomfort . It is especially suitable for people with sensitive skin or damaged hair