Standard Magpul PTS mags are made by Magpul, and are made from polymer plastics that are the equivalent of their real steel counterparts.
Green label Magpul mags are made by Star, and are made from ABS plastic - still fairly tough, but not as tough as the polymer built ones (i.e., don't try running a car over them or dropping them from 5+ metres up).
Green labels may require some work to make them feed consistently (lubing, lip modification, etc.) whereas the standard polymer version should work without any mods.
I use the green labels and had some initial teething issues. Once those were resolved, the mags have been operating without any problems.
VFC SCAR-L - VFC SCAR SSR - KJW Hi-Capa 5.1 - CAW M79
The Three Sisters - WE G39 E/K/C
Originally Posted by kalnaren
Stalker stays where he is.
His BB's fly across the country to hit their target.