I just purchased some G20 mags locally. They had some with a #2 follower that had the ambi cut, and some with a #3 follower without the ambi cut like the one in the pic. There aren't that many of the ambi Glocks out there, I don't blame them for not supporting them anymore.
GLOCK Certified Armorer, GSSF member, NRA Life Member
Currently: 17x2, 17L, 19x2, 20x2, 22, 23x6, 24x2, 34x2, 35+1, AA LE 17-22 on G31 frame, Olympic Arms K9-GL
Have owned: 21, 26, 27, 29, 30, 31, 32, 33, 36