4 pack of tubes - for you and all your unprepared friends
the 4 pack just comes in handy. friends can show up unprepared. the presta valve will work on presta or schraeder rims, and the long stem works in any size rim. a 29er tube will fit into a 29er or a 26 inch rim in a pinch. I like these cause i can get the core out, and add a bit of sealant.