FilterPal is for dry particles only.

FilterPal HD means Filterpal Heavy Duty. It is our largest version of FilterPal. We retired the name, and it is now called FilterPal Large.

Yes. 

Our size chart is here.

The color. They work the same.

Yes. FilterPal was tested in the U.S.A. by Professional Testing Laboratory

FilterPal captures particles estimated at 1 μm and above. It reduces dust emissions by an estimated 50%.

Yes. Please send queries to david@filterpal.com, and someone will get back to you.