Strong, lightweight and relatively low cost are what makes the polyester roundsling popular today. Roundslings are constructed by using loosely twisted strands of high strength polyester fibers and using a specially designed machine, the strands are pulled through a tough, woven tube to create a strand bundle. Altogether, the bundled polyester fiber strands and tube material form to make a strong, light and high performance lifting sling.
Though the sling can be configured to work as an eye x eye type sling, polyester roundslings are most commonly offered as an endless grommet shape.
The more fiber strands contained inside the tube, the higher the capacity of the sling. And to distinguish the different capacity slings from one another, the world has pretty much settled on a color scheme for each of the standard capacities. For example, purple tubing is the color for roundslings with a vertical capacity of 2600 pounds, green is 5400 pounds, yellow is 8400 pounds and tan is 10600 pounds. These are also the colors and sizes offered by E-Rigging. Each of these slings come in various lengths.