We are a truck inner tube manufacturer in China. Great fun for river tubing, the lake, swimming pools, and so much more! Tubes measure between 28\\\\\\\'\\\\\\\' to 48\\\\\\\'\\\\\\\' across when inflated (depening on how much aire you put in it). Manufacturered with short valves for your safety instead of the long elbow style valves. Some of the many uses include: River tubing Snow tubing Swimming Pools Use to Float pool Covers Center Hole Measure Approx 22\\\\\\\'\\\\\\\'-34\\\\\\\'\\\\\\\'