These are good general riding tubes. I live in the Denver area and we are plagued with goat head thorns. They will penetrate anything. They don't stop flats but they are decent low cost tubes that hold air for days without requiring a top off. They don't have removable valves.
A SUPER value for the $...The only reason I didn't rate at 5 stars is due to the fact that it will wear out..it isn't bullet proof..but that being stated..for the money..tough to beat.