Vent filters are available in four hose sizes and available in two types, either as a replacement for an existing filter
or as a complete filter with hose fittings and a mounting braket for new installations

Name: Sanigard Holding Tank Vent Filter
Model Number: 310001
Description: Replacement Vent Filter 5/8" and 3/4" 
Contains odor-removing filter materials to keep your boat smelling clean and pleasant.
Each cartridge is good for an entire season and is easily replaced for a fresh start.