NOTE: The PHD2000 series are legacy pumps with high prices because components are becoming obsolete; it only makes sense to purchase these if you must have an exact replacement. Otherwise see the PHD ULTRA pumps for more modern features including touchscreens.
To choose a pump, determine: (1) how much programmability you need, (2) which syringe rack suits best suits your application.
HA2000I - Infuse Only - For applications such as microdialysis that require high accuracy and low flow rates without the need for fluid withdrawal or complex protocols.
HA2000W - Infuse/Withdraw - Adds the ability to withdraw fluid and refill the syringe.
HA2000P - Programmable - Use for complex protocols. For example: deliver a bolus then ramp down to a steady infusion rate; deliver doses of a drug several times a day for several weeks; deliver a small dose of a potent drug, then send a TTL signal to a separate pump to flush saline through the line.
Basic dual syringe rack (included) - Holds one or two syringes of the same size, from 0.5µl to 140ml.
6 to 10 MultiRack - Holds ten syringes from 0.5µl up to 20ml in size, or six syringes up to 60ml in size.
4 x 140 MultiRack - Holds up to four syringes between 30ml and 140ml in size.
Microdialysis Rack - Holds four 0.5µl to 10ml syringes for microdialysis with up to four probes or other ultra-low flow applications. Independently adjustable thumb screws let you infuse with different sized syringes simultaneously.