Get Watts Premier Post Carbon Push Button Blue Filter, along with many other Watts brand replacement filters.  We also have a , with all filters included.

This filter has a 5-Micron Carbon Post Filter - made of high-quality activated carbon to reduce chlorine taste and odors.

This filter fits the  RO-PURE/RO-4 Premier RO-PURE Reverse Osmosis and filtration system. This Post Carbon filter is made up of high-quality active carbon which enhances the flavor and taste of the water. This filter will only work with RO-PURE and the Filter Pure system.

Features:
Filters down to 5 microns
Reduces chlorine taste & odor
Filter rating: 1 year
Easy to install

Specifications:
The recommended filter change is once a year*.
*Note: Filter life may vary based on local water conditions or use patterns.

Product dimensions:
9 7/8 inches x 2 inches