These are quality inexpensive tubes. The valve stem is threaded all the way to the base and there is a nut that goes over the threads. This gives you the ability to secure the valve stem in place making installation incredibly easy.
I have over 300 miles on these tubes with no flats. I am using good flat resistant e- bike tires. There is minimal weekly air loss. Far surpass original bike tubes as well as other replacements.
Great tube well made and strong.
Valves are stainless and screw top (presta)
Sturdy. Rubber ring around valve stem to tube are strong and resist flex unlike other cheaper made tubes.
So, a pair of these went inside the new cruiser tires I purchased to restore the Specialized Shark cruiser. Look that bike up - it's pretty cool. My daughter loves the look and ride of it with the white Conti retro 26ers.
Normally have great luck out of continental tires and tubes. But the first tube I had blew up while inflating at just over 40 psi. Had to run to the local bike store and pay twice the price for a lower quality tube. Kind of disappointing, but the other three held.
I got these tubes to match with some Continental tires bought at the same time. While I was installing the first tire, the tube blew out at about 50 psi, about a 4 inch long split. Could have been pinched, or a one in a million defect, I don't know. I never had a tube blow out like this before in 40 years. But since this was for my wife's bike I switched for some older Specialized tubes I had on the shelf that were a bit thicker rubber.
I run 1.5 semi-slicks on my mountain bike for road use. The standard 1.75-2.1 mountain tube does not install well and pinch flats. This tube solves the problem. The rubber thickness is a bit more and more reliable against flats. I have over 15 bikes and I am convinced the Conti tube is the best! Rumor has it that all tubes come from the same factories in China but for whatever reason the Conti tubes are the best quality, easy to install, but most importantly reliable. Get them!