The Thermally Reactive Advanced Protection (T.R.A.P.) Breather assembly protects the fluids in your storage tank from airborne particulate moisture contamination and ambient moisture. It combines a high capacity 3 micron air filter with a deliquescent breather that dries itself when air is expelled from the tank. This self-regenerating capability of T.R.A.P. enables extended life and functionality. Keep your fluids clean and dry with a Donaldson T.R.A.P. Breather.