The Pentek 255599-43 includes the following filter media:
The Pentek GS-10ALS-G-1/4" 20 Micron Inline Filter is a replacement inline water filter cartridge constructed with hexametaphosphate and coconut shell carbon. This carbon shell filter cartridge reduces chlorine taste and odor through its 20 micron rating. This 20 micron filter effectively reduces waterborne contaminants to improve the taste and clarity of your drinking water.
Pentek GS-10ALS-G-1/4" 20 Micron Inline Filter specifications: