The diameter of your solar tube directly impacts how much light enters your space, with options typically ranging from 10 to 22 inches to accommodate different room sizes and lighting needs. Understanding factors like your roof structure, room dimensions, and desired brightness level will help you. The Eco Worthy web site doesn't specify the size of the mounting plate at the base of of the main pole, but it has eight bolts and I'd guess is 6" square. Assuming that's correct - I will obviously measure once I have the parts in hand - what diameter Sonotube would be recommended for the mounting. Some of the most important questions for most installers and DIY solar enthusiasts concern mounting solar panels. There are many high-quality mounting solutions on the market, such as Unirac, IronRidge, PowerFab, Quickmount PV, Schletter, etc. You're balancing panel efficiency, roof integrity, labor costs, and project timelines. One of the most critical, yet often underestimated, pieces of this puzzle is calculating the precise number and spacing of your solar mounting system components. Other patents pending. SolarMount® is the most versatile system of components available for mounting PV modules. They are 1⅛” tubes but I can't fine any 1⅛” U-bolts to hold down the panels. Seems like it is a nonexistent size, not even McMaster-Carr has them.