A replacement Golf Filter Case Only. The Golf Filter is for use with 12.4 gal hard tanks. This is the 3/8″ size that is compatible with the 3/8″ OD tubing and AQUAvalve5. It is inserted into the pipe end inside the reservoir once the pipe is pushed through the Top Hat Grommet. It can be easily serviced and will float to the top if it comes detached from the tube, this will not happen if you make sure you have pushed the filter firmly into the tube.