And finally, we learned why Kinetic’s fluid resistance units are so reliable. Most units have a shaft running from the roller to the fluid-filled resistance unit. The fluid is kept contained by seals as the roller spins away. Well this works ok for a while but after many years, the seals will deteriorate and leak. The Kinetic unit avoids this scenario by eliminating the shaft into the resistance unit. Instead, they use magnets on both the roller unit and the resistance unit. The magnets line up and transfer the energy from one side to the other by spinning together.