Looking for a replacement carbon filter cartridge for 4×21" housings?_x000D_

_x000D_

This is it._x000D_

_x000D_

These one-time-use carbon filter cartridges fit the 4×21" housings from many manufacturers._x000D_

_x000D_

Filled with our high-quality activated charcoal carbon, these filters will remove all of the chlorine and chloramines in your water to make it safe for your RO membrane to process.