The band on the left is a standard 904 band and is 1.3-inches wide. The most desirable band is the one that came standard in 904s behind 360 engines and were 1.75-inches wide. While our A999 came equipped with the wider band, we could not get a replacement in time, so we went with the next best option, an A500 overdrive band (right) that is 1.6 inches in width. Will it hold up to the punishment of our Stealth Bomber? Only time will tell.