Yes, the FAB Defense Universal Polymer Magazine Coupler is designed to work with AR15 pattern magazines in all capacities.
The FAB Defense Universal Polymer Magazine Coupler should work with those magazines.
The FAB Defense Universal Polymer Magazine Coupler will not be large enough to fit a 12 gauge box magazine.
Yes, the FAB Defense Universal Polymer Magazine Coupler will work for Steel AR47 magazines.
Yes, the FAB Defense Universal Polymer Magazine Coupler will be compatible with those magazines.
Most likely you will not have to take apart the FAB Defense Universal Polymer Magazine Coupler because it was designed to have enough space between each magazine to accommodate the size of an AR15 magwell. Your loader should still work fine, although it may be a little more of a pain to load each mag.
No, this is for GI style steel magazines.
No, this is for GI style steel mags.
No they will fit the 7.62x39 Mags since all the listed of firearms are 5.56 Nato or 5.45x39. And with the listed firearms the mags themselves would need to be fit mil spec metal magazines, but not polymer magazines.
It is one coupler that comes with 2 attachment points for your magazines, as pictured.