I needed to find a good quality tube for my hauling bike. After a few weeks of use on the roads, I not once had to break out the tire repair tools! ) (New rim tape also helps.) I did add some air but with weather expansion-contraction, that's normal. Very pleased.
I bought the Continental 1.752.5 MTB 26 tubes with the Presta valves to install with my Michelin Country Rock 26 1.75 tires that I bought at WesternBikeWorks. I store my bike in my home, but I haven't had to add air in the tires for 3 weeks and the pressure is still the same. With my old tubes, I had to add air weekly. These tubes have exceeded my expectations. Will buy again!
Reliable quality and competitively priced. They last and last but replacement is eventually necessary. It's not if but when.