2.5 inch hose adapter with curved flange

thingiverse

I needed the ability to direct airflow from my soldering work into my air filter. I was able to use this adapter along with a sheet of foam with a hole to cover the inlet of the air filter and direct the airflow through the adapter. This does put extra strain on the air filter motor, so it's not something I recommend leaving in place for long periods of time. This is a hose adapter flange to fit snugly against a [Levoit Core 300](https://levoit.com/products/core300-true-hepa-air-purifier) air filter. I measured the diameter of the air filter at 212 mm, and the flange fits reasonably well against the curve with a piece of foam to help improve the seal around the flange. The suction of the motor is enough to hold the foam and adapter in place without any additional hardware.