I guess I need help, How do I determine what model number my 600 sportsman is? I need to buy a new gas tank, when I go to the web site and pick the 600 I am asked if it is a "A04CH59AF" or a "A04CH59AK",,,,, I can not find anywhere on the machine where it tells me which one of these belongs to this machine. can someone please enlighten me?

I guess I need help, How do I determine what model number my 600 sportsman is? I need to buy a new gas tank, when I go to the web site and pick the 600 I am asked if it is a "A04CH59AF" or a "A04CH59AK",,,,, I can not find anywhere on the machine where it tells me which one of these belongs to this machine. can someone please enlighten me?