4/8/10Pcs 13x13~200x200mm White Square Plastic Blanking End Cap Chair Table Feet Cap Tube Pipe Insert Plug Decorative Dust Cover - AliExpress
Prescott Plastics 2" Square Plastic Hole Plugs, Square Tubing Inserts, Black End Caps for Metal Tubing, Fences, Glide Protection from Chair Legs and Furniture (50 Pack) - Walmart.com
Plastic End Cap Square - Black 50mm (pack of 2) - Icon Fasteners
Square Tube End Caps - Plastic Square-Shape Tube End Caps
Plastic Square Tube End Cap
80mm Square Plastic End Cap – Motorhome Towbar & A Frame Specialist
Square Plastic End Caps Blanking Plugs Box Section /Tube Inserts / Black | eBay
Hillman 2-Pack 1/2-in x 1/2-in Black Plastic End Caps in the End Caps & Screw Protectors department at Lowes.com
Amazon.com: Prescott Plastics 1 1/2” (38.1 mm) Square Plastic Plug Insert, Black End Cap for Metal Tubing, Fences, Glide Protection for Chairs and Furniture (10 Pack) : Industrial & Scientific
10 Pack: (1.75" (1-3/4"), Square Plastic Plug, Tubing End Cap (14-20 G) for Inside Length 1.59"-1.68" Width 1.59"-1.68" | Furniture Chair Glide Inserts | Fencing Post End Inserts | by SBD - SB Distribution Ltd.
Amazon.com: 4 Pack 1 Inch Square Plastic Plug Tubing End Cap Suitable for Square Tube (Black-4Pcs) : Industrial & Scientific
50mm Square Plastic End Caps For Steel Box Section Pack of 10 | Fastco