Sorry you was on a long wait i've just got back on line due to many days of technical problems .
Anyway if you still need assistance i will answer you .if you have already got an answer then please let me know and don't rate .
You Mitsubishi A/C fluid is..
134a is an HFC refrigerant which has been used to take over from the CFC F12 that was used in older vehicles .
R-12. vehicles .
You should have the 134a and not the F12 if you have the big valves to fill like the pic attached then you have the 134a if just a small Schroeder type valve then this will be a older F12 freon .
Need further assistance then please get back to me .