(Pack of 4) - 1 1/2" - 1.5 Inch Square Black Plastic 14-20 Ga ( 1.35"-1.42" ID) Tubing Plug, End Cap -Steel Fence Post Pipe Tube Cover - Furniture sliding Inserts - End Caps for Fitness Equipment Hardness: Durometer 50D. Maximum Temperature 150 F Flexible ridges or straps snugly hold these plugs in place. Compatible Tubing Wall Thickness 14 - 20 Gauge Custom Made Made With High Grade Plastic LDPE