a resonator. Not that you need it for sound but it may help with your installation. They make them in several configurations and allow for easy project design. I used one to keep "everything tight" due to a space constraints because of my small cockpit. Mine mounts to the bottom of the vented loop to drop the hose down to just above water level and via a 90 degree bend sends the water aft. This keeps the hose at the bottom of the locker and the hose doesn't make a huge arch but is kept close by the 90 at the base of the resonator.