The Donaldson Spin-On Air Dryer is designed to provide reliable and efficient air drying for your Freightliner, Kenworth, Mack, Peterbilt, Volvo Truck and Fendt Tractors. This air dryer is designed to be a stand-alone unit and does not require any additional equipment. It features an outer diameter of 140 mm, a thread size of M39 x 1.5. This air dryer is designed to work longer with its new desiccant. This product is efficient in air drying. FleetPride is your First Click in Heavy Duty®.