WATER SAMPLER Features: Ideal for use with Model 407 bladder pumps or Model 408 double valve pumps 99 customizable sampling presets Use Solinst Model 464 in automatic or manual mode The Solinst Model 464 Electronic Pump Controller is available in 125 psi or 250 psi versions, and uses 4 AA alkaline batteries that last up to 100 hours of normal use. These Controllers can also be operated manually if your batteries run out in the field, using only a compressed gas source. The 464 Electronic Pump Control Unit has automatic preset sample modes from low through high flow settings. In addition, up to 99 user-created flow rates can be saved in FRAM memory. The Pump Control Unit allows faster purge rates and precise low flow control to ensure a representative sample at 100 ml/min or less when sampling for VOCs (Volatile Organic Compounds). These convenient Pump Control Units are rugged, dependable and suitable for all environments. Quick-connect fittings allow instant attachment to dedicated well caps, portable reel units and to an air compressor or compressed gas source. Includes: Solinst Model 464 Electronic Pump Controller 125 psi Drive and supply lines 4 AA alkaline batteries