I have a zero turn that has Carlisle Turfmasters on the in the sise 24 x 12.00 - 12 NHS. They are tubeless tires. As an aside, I have never had such troubles with flats as I have had with a zero turn. Running tractors I have had two flats in 32 years. With this machine I have had four flats in two years. The fronts I fixed with slime. The rear on one side I fixed with slime and the other had what seemed to be a porosity in the sidewall, so I put a tube in it. The Carlisle dealer stocks a 24/26 x 12 x 12 tube; that is what I used. Yesterday that same tire went down. I got it apart and was amazed to see the tube showed signs of being too big. It had lines from what I assume to be wrinkles and folds. A pin hole had developed at what I take to be a chafing point. I have a good 40 years of experience working with tube type tires on trucks, cars, and motorcycles. I know how to get a tube in place and inflate it with no stem, ensuring there are no wrinkles. I was careful to do that. Inflating the tube outside of the tire makes it apparent, I believe, that it is too big, and the ID of it is not a smooth radius. Am I missing something here? Is there a better tube size to use in this tire? Thank you.