Stainless steel Model 407 Bladder Pumps provide consistent, accurate, reliable groundwater samples in all applications. Ensuring no air/water contact during operation, pumps are ideal for VOC sampling. Teflon® bladders are ideal for dedication. Inexpensive polyethylene bladders are also available. Stainless steel pumps are effective at any angle, to depths of 500 ft (150 m), and are ideal for low flow sampling.