Grommet - 1 in.

These General Hydroponics GH4166 1-inch grommets are designed for use with AeroFlo chamber spraylines. They create a snug fit when creating custom hydroponic systems and can replace existing and worn grommets. These 1-inch grommets works like a bulkhead fitting, allowing connection of 1-inch tubing to a tray or other containers within the hydroponic system. Comes in a bag of 10 grommets.