Ranked 1st in our list of recommended replacement filters and sells for $32.99 (as of 23/01/2019 09:08 PST details ) , more than 86% of the Booda 50311-12PK-MC reviews are positive. With features such as traps both urine amp feces odors using a combination of charcoal and zeolite particles. activated charcoal is able to absorb and trap the odor by chemically binding to it. zeolite has a cage like structure and works with the charcoal to trap odor molecules for dual protection from unwanted odors. and minimizes cat box odors so you home smells clean and fresh., it is indeed our top pick among replacement filters.