Rocky's 336 4" x 20' Commercial Tube Set for Reel System, is designed to work with all of Rocky’s Commercial Systems. Our Commercial Tubing is also designed to work with the #3, #4 and #5 Residential Systems, providing additional rigidity for pool owners that want to make sure their reel system never sags or for those that are using a thicker than normal solar cover. The 4" Commercial Tubing is specially designed for our products and is manufactured in Canada. This high quality tubing is anodized and uses a 12 sided design to increase the strength and lateral integrity. Rocky’s 4" Commercial Tubing can be custom cut to fit any pool shape and size