I think INCA in Nashville made the tanks for the 221 but,,,,you will need to find another 221 owner to get the model # off the tank. Other wise the air head at the phone is useless as a mammary glands on a male steer. I've dealt with them over Stratos and Champ tanks in the past and they are pitiful to say the least. They need the model number on the tank. Worse case if no one can help you here call Deano at the plant ext 2007 and he can give you the number to relay to INCA. Good luck. C&O may have one. Thank your friend immensely he just cost you about $300.00 .