FSW301 is a FSW300 series low cost flow switch that comprises a paddle system with a attached permanent magnet. Above this magnet is a reed contact, positioned outside the flow of fluid. A second magnet with opposing poles creates the force needed to reset the switch to the no-flow position. When the flow is interrupted, the paddle returns to its starting position, causing the reed contact to revert to its initial state. The force required to push the magnet back is provided by the repelling action of the two magnets. Using magnetic force rather than a traditional leaf spring makes the switch considerably more stable over time and less sensitive to pressure peaks. The reed contact, which serves as the sensing element, consists of two ferromagnetic contact blades enclosed in a glass bulb filled with inert gas. This design minimizes wear from contact arcing and allows for a useful life of up to 100,000,000 switching cycles.