I bought 5 of these at once. Installed 2 right away. One of them blew out while riding, not from a puncture but from the valve stem separating from the tube. Not sure if it is a manufacturing flaw, or if I was just unlucky. I was out on the road and had an old spare so I haven't used any of my remaining three. The other tube has been great for the last three months of riding 70-100 miles a week both on the road and up canyon dirt trails.
I have about 26 mountain bikes in my fleet and I've struggled to find the right tube. We would buy discount tubes only to go through them in a few weeks. These tubes hold up very well and I really like the metal stem.
It's very thick and heavy! If your main purpose is to avoiding flat, it definitely does exactly what it does! But it will slow you down in about 3 to 4 miles per hour. I took it out of my road bike for a thinner, lighter tubes after 6 months of riding almost every day along all trails in southern California and I am very happy with the speed that I have gained.
Great for comfort bike, but not road bike if you want to go fast.
With puncture vine being a perennial challenge, a removable valve core allows me to easily add Stan's sealant in the tube. In the past two months I have traveled over 1,500 miles with these tubes, both on and off road. During that time I have removed countless thorns without a single flat.
These are high quality tubes that I have used frequently in the past. My only complaint is the size of the tubes when placed in a saddle bag. The rubber around the stem is quite thick, making it hard to get them wrapped into a compact ball. I have had thinner tubes, but not with as much anti puncture success. I will continue to buy these tubes.