PMAGs different generations

[SMILEY]

How do you tell the different generations on pmags .I have some with green and black followers . Is one better than the other ? How many different generations are there ?

 

[SirIsaacNewton]

I know the dust cover doesn't clip onto the bottom of my gen 1 pmags they also have numbers next to the window on the mag that show how many rounds are loaded. There is no round number on the gen 1 pmags. I know nothing about the reliability differences but I haven't had a single misfire with my any of my dozen pmags. Good luck and if you find any pics post them.