22.23mm (7/8") Square Tube End Cap (ENDCPSQ22) | Richmond Wheels & Castors NZ
S.S. Square Tube Spire Top End Cap | Metal Railing and Accessories For Pipe | DAH SHI
Tubing Caps 4" Square Black Plastic 4x4 inch, Finishing Plug, Pipe Tub – JSP Manufacturing
How to Cap Square Tubing : 8 Steps - Instructables
Square Tube End Cap 16 mm | Aluminium Warehouse
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 Furnitures (10 Pack) : Industrial & Scientific