Quick Answer
A shower filter sits between your water supply and showerhead. Water passes through a replaceable cartridge containing filtration media that is designed to reduce selected substances before the water reaches you.
Problem
Shower water can contain substances you would rather reduce — such as chlorine from treatment or sediment from plumbing. Without filtration, that water reaches you directly.
Product Recommendation
The ZOOSHEN Essential Shower Filter and ZOOSHEN High-Output Shower Filter both use a replaceable cartridge architecture. Replacement cartridges are available individually or in multi-packs.