Pre-filters

Washable pre-filters. Available in two styles. Please determine the number of screw holes you will need before purchasing. 
Nomad Models and older generations of the Model S will need the square 4 hole pre-filter. 
Newer Model S flow hoods will require the round 2 hole pre-filter.
To install the pre-filter, you will need to get inside your flow hood and remove the fan/ screws. Then, proceed with installing the pre-filter to the external side of the backboard using the existing screws. Reinstall the fan on the inside and tighten the screws and nuts. 
Older Model S flow hoods will not require the steps mentioned above. The pre-filter will be installed on the external side of the backboard. Start by removing the fan guard and then place the pre-filter in its place and mount with existing screws. Should the screws come loose at any point from re-working those holes, use wood glue to anchor them in. 
Washing instructions: Remove the pre-filter and wash with warm water and a gentle soap. Allow the filter to dry before re-installing. Additional sanitization steps can be used by spraying the pre-filter down with 70% alcohol and allowing it to dry. Please note that this will decrease the life span of your pre-filter. 
If you need any assistance, please reach out!