I have this cheap $99 fun fly and only the stock tank fits. No other tank on the market would fit. The mistake I made was using the stopper that came with it. It leaked fuel all over the nose of the plane and caused my main gear to break from weakening the balsa. I found out that the stopper was not leaking on the the tank, the copper tubing was just sliding in and out on the stopper no matter how tight I made the stopper. So I will never use a cheap stopper even on my cheap crashable planes. I will always use the Dubro, Sullivan, Hayes stoppers even if I am forced to use the stock tank. It took me only 15 minutes to pull out the tank dry out the plane and CA the gear back in place. I had to wash all the fuel out of the foam padding as well.