With the Pumpin Gum Ball, changing liquid is no longer a problem. This little helper removes the majority of old liquid remnants out of a system. The Pumpin Gum Ball creates pressure in the system and removes the drops from every corner through a constant pumping. One side has a ?" internal screw thread. The Pumpin Gum Ball can be connected by removing a connection at any point in the system, splitting the circulation. Anyone using a fillport has it even easier, and can simply connect the ball there.