Amazon.com: Rubber Grommet 1/2 Inch, Hydro Rubber Grommet Donut Type to make Waterproof Seal in DIY Hydroponic Systems and 16mm or 1/2 Inch Barbed Elbow Tee Straight Y Connector and Vinyl Tubing (
Rubber-Cal EPDM Rubber Sheet- 1/4 in. Thick x 2 in. Width x 36 in. Length - Black - 60A Durometer 31-016-250-002-036 - The Home Depot