Performance PVC - 4-Way PVC Side Outlet Tee Fitting, Furniture Grade, 1-1/4" Size, White (Pack of 4): Amazon.com: Tools & Home Improvement
Gardeningwill 4 Way 1-Inch Tee PVC Fitting Build Heavy Duty Greenhouse Frame Furniture Connectors (Pack of 4) - Amazon.com
Formufit 3/4 in. Furniture Grade PVC 4-Way Tee in White (8-Pack) F0344WT-WH-8 - The Home Depot
15Pack 3/4Inch 4 Way PVC Fittings, Heavy Duty PVC Elbow Side Outlet Tees, Furniture PVC Tee Corner Fittings for Building PVC Furniture Greenhouse Shed Pipe Fittings Tent Connection: Amazon.com: Tools & Home