Cargo brand Endurance Luggage
 

I bought this tank bag at Cycle Gear and it is a good one. It fits the Superhawk tank well with the magnets and will hold a lot of stuff like my lunch that I take to work. They make a smaller Sports tank bag that also fits well on the tank but I needed a little more room. It is expandable in height which probably is more than I need but at least the option is there.

Cargo Endurance Luggage is the brand and it can be found at Cycle Gear if you have one in your area. The model number is CAR001 for the tank bag and CAR006 for the smaller sports tank bag. The smaller bag was $75 and the larger one I bought was $89.

I bought a tank bag because I put the cover on my passenger seat where I used to put my tailbag and wanted to leave the cover on all the time. This is a well built bag and the fit is good on the tank so I recommend it.