Additional Details ------------------------------ Product description: QMP540 is an easy to install shower filter. Our filter has been shown to effectively remove damaging chlorine, iron, and sulphur at the source as well as help keep mold and mildew from forming in your shower. Our streamlined design has a unique back-wash feature which will reverse the flow of water to remove any sediment buildup that can cause other filters to fail prematurely.To install, simply unscrew your existing shower head from the shower arm, screw on the new shower filter, and screw the shower head back on. The filter works best if used with a new or cleaned showerhead. (Shower head not included)