How new? I have a 2012 Mazda 3 (Skyactiv). Stamped into the plastic tank, near the cap, it says FL22. If your coolant is a dark, somewhat forest green color it's FL22. There is no aftermarket version. Some will say you could use an Asian multi-vehicle formula (Zerex). FL22 doesn't need to be replaced until the car is at 122,000 miles. It is available in premix only (55% coolant/45% water) from Mazda, or as a concentrate from Ford, called "Specialty Green."
I have been adding 4 oz of RMI-25 to mine every 15,000 miles. I haven't had to top off yet (41,000 miles). Based upon what I learned about RMI-25 I may run this coolant a lot more than 122K miles - with pH testing.