For standard applications and liquid transfer. Hei-Flow Core pumps include premium safety standards and features for superior ease of use and reduced cost of ownership.r- Adjust the variable speed on the analog control knob from 10 – 600rpm. Your speed is held constant even under changing loadsr- Electronic speed control at an accuracy rate of ± 2%r- At the press of a button the pump operates clockwise or counter-clockwiserSupplied without pump heads. Please order separately.r- Power supply: 230 V.