I bought 2 inner tubes and they arrived super fast (I placed the order on Sunday and they arrived Tuesday morning, which seemed strange to me because I live in the countryside). I put one on the rear tire myself but when I inflated it, it was losing air and wouldn't hold for even 1 minute. I haven't put the second one in the tire yet but when I inflated it, it seems to hold. I believe that with the first one I made the mistake and punctured it myself and that it wasn't like that from the store.
Note: I took them to a shop to have them installed and after he patched them and sealed the holes (that I had made), when he inflated them, they would open up on their own as if they were rotten. He patched them again and they would open elsewhere and it's not the tire's fault. DO NOT BUY THEM!!!!!