Our dual action drum vent plugs are resistant to harsh weather, which makes it the best choice for outdoor applications due to the EPDM gasket. This gasket also provides chemical resistance while being resistant to heat, UV exposure and aging. The EPDM is FDA approved so it can be used with your food products. The dual action vent plug has a micro-porous gauze vent. This vent allows two-way venting, which can be used for either pressure or vacuum relief, and it begins venting at any pressure differential. Use these vent plugs to help prevent non-flammable liquids from leaking during normal sloshing while transporting and handling your product. Remember, these are not designed for horizontal drum storage.