MasterCool Vacuum Pump Activated Carbon Exhaust FilterCarbon Exhaust Filter for MasterCool Pumps Replaces Koby Junior (US Patent# 3169112A) MasterCool Vacuum Pump Activated Carbon Filter for use with Mastercool pumps. This filter will adsorb contaminants such as oil aerosols, oil vapors, certain other hydrocarbon vapors, and trace moisture. They also trap all foreign solid particles and bacteria down to 0. 5 microns in size. Key Features: Purifies Exhaust Gases from Vacuum Pumps Up to 19 CFM 0. 5 Micron