Norigen micro fog filter model 13-002-101 Norigen micro fog filter model 13-002-101 includes an observation glass, hand valve and gauge. This filter is used in pneumatic systems to remove moisture and particles from compressed air, helping to maintain clean and efficient operation. The sight glass allows for a visual check of the filter's condition, while the manual valve allows the user to control the airflow. A pressure gauge helps monitor and maintain system pressure levels. This component is vital to ensure the longevity and correct operation of pneumatic equipment.