Grommets are used to attach barbed fittings to trays, buckets, etc.
The 1/2" Grommet accommodates all the 1/2'' Barbed Fittings we sell. It's the same fitting used to attach the Drain Level Tube to the side of the bucket on the WaterFarm, Power Grower and BGH bucket systems. The 1/4" Grommet will accommodate the 1/4" tubing we sell. The 3/4" grommet is perfect for attaching a 3/4" Inline Shut-Off Valve to your reservoir for easy draining.