The Gilian® 3500 & 5000 air sampling pumps are industry-leading devices that offer superior back-pressure performance, reliability, and ease-of-use. With flow rates up to 3500 & 5000 cc/min respectively, these pumps are perfect for sampling particulates, vapors, gases, and metal fumes. Advanced features of the Gilian® 3500 & 5000 pumps include an air flow display that holds calibration for 30 days, even with atmospheric changes, and the highest back-pressure capabilities in the industry for any personal sampling pump. These pumps are the ideal solution for any workplace that requires accurate and reliable air sampling.