An alternative to oil-sealed piston vacuum pumps, the units reportedly require less maintenance and eliminate contamination of back-oil migration and emissions. Other advantages include elimination of contaminated waste water through air cooling, less particle deflection and buildup with screw-compression stage, and the ability to accommodate boosters for higher speeds at lower pressures.

Leybold Vacuum USA, 5700 Mellon Rd., Export, PA 15632, (800) 764-5369,