Review on Plastic Square Tubing Fitness Equipment by Daniel Mandal

Make sure you buy the right cap. Knowing the outside size is important, but you also need to know the inside size of the square grout you are using. This is because there are two sizes of inner caps. One cap size is for heavy, heavy gauge steel tubing and the other inner size is for light weight, thin wall square tubing. Once you know this, you can get started.