This Eisco Labs siphon / lift pump is constructed from high-quality borosilicate glass and demonstrates the operating principles of a basic suction pump. The pump measures approximately 11.25 inches in the down position with 3.75 inches of plunger movement. The bottom is equipped with filter material, and the plunger features a thread-wrapped ball to create a seal. The outlet hole measures approximately 0.25 inches in diameter and the inlet measures 0.375 inches. Ideal for physics classroom demonstrations of fluid mechanics, atmospheric pressure, and the operation of mechanical pumps.