This popular style offers greater filtered air flow with better protection against clogging from dirt accumulating on the equipment. The design incorporates more vent ports and they are located higher on the body of the unit for greater clearance. The standard Style 1637 is provided with a screen and two layers of Nylon for filtration. It can be ordered with a screen filter only, or non-filtered for straight-through air flow. These breathers are ideally suited to maintain equalized pressure in axle differentials and transmissions, also in industrial gearboxes and transmissions. This prevents damage to seals due to change in ambient temperatures, on-off cycles or during filling.