Parts › 4031 - Vacuum Pump exhaust Muffler (2" male thread) Image 1 of 1 4031 - Vacuum Pump exhaust Muffler (2" male thread) $220.56 Quantity: Purchase Added! You Might Also Like 3021 - Busch Vacuum Pump Casing O-ring $30.00 4015 - Flow Sensor $350.00 Aluminum Louver $66.00 4060 - Water Feed Hose $15.00 5186 - Cube Fuse Holder $30.00