Busch designs and manufactures a wide range of high performance vacuum pumps and systems that are used in many industries around the world. Busch LLC. is an ISO 9001-2000 registered company, committed to quality vacuum products, customer satisfaction, and prompt after-sales service. The Busch Huckepack Mark 4 vacuum pump is a two-stage, Once-Through-Sealing, rotary vane design. The Mark 4 design allows engineers the flexibility and performance they need for their particular process including the choice of several sealing fluids with different vapor pressures