Found 11 more GCs in Forest City, NC. I bought them out. Also on their shelves was GC M02 with the 502 rating and the black and red lable. They also had quite a bit of the M01. I didn't buy the M01, but I did buy the M02 . I don't know why because I only got 2 quarts and I don't know if "it's the good stuff or not" or whether mixing it with the others is ok. BTW- it had been on sale over the weekend and they had forgotten to take down the sign on the shelve so I got it at a bargin. Can anyone tell me the difference between the MO3/4 and the M02?