New Flex-I-Liner Thermoplastic Sealless, Self-Priming Pump with MAC Motor. New Old Stock, found in an inventory we purchased, Pumps seem to be in great shape unsure if they are in working order though, we were unable to test them. Through some research we found that this specific type of pump is used in a wide variety of settings, it is a rotor mounted on an eccentric shaft that oscillates within the flexible liner creating a progressive squeegee action on the fluid trapped in the channel between the line and the body block.( See diagrams last three pictures). Pump does have 3/4" Hose Connections.