A peristaltic pump is a type of positive displacement pump used to pump a variety of fluids. The fluid is contained within a flexible tube fitted inside a circular pump casing. A rotor with a number of 'rollers', 'shoes' or 'wipers' attached to the external circumference compresses the flexible tube. As the rotor turns, the part of tube under compression is pinched closed, forcing the fluid to be pumped to move through the tube. Additionally, as the tube is compressed, the fluid ahead of the compression is forced to move through the tube, and as the tube returns to its natural state after the passing of the cam fluid flow is induced to the pump., This unit is manufactured by MasterFlex.