Amazon.com: (Pack of 25) 2" Square (14 - 20 Ga ) Black Plastic Tubing Plug, 2 Inch End Cap 2"x2" (for 1.85" to 1.92" ID)- Steel Fence Post Pipe Tube Cover Insert | -
Insinger 4820-03320 Plug, Wash Arm End 3/4-10 Hdpe
Black Vinyl Cap - 5/8" Cap ID x 1/2" Inside Length | U.S. Plastic Corp.
Amazon.com: (Pack of 8) 1 1/2" Round (10-14 Ga 1.24" to 1.33" ID) Plastic Tubing Plug 1.5 Inch End Cap - Steel Furniture Pipe Tube - Chair Leg - Table Glide Insert