Matrix AK to M4 Conversion Key Adapter
(For AK Airsoft AEG to use M4 Series Front End)

"Ordered to use in an old TM AK under-folder. No instructions, but relatively straight forward to install. Minimal fit issues on the TM. Stock screws from the bottom of the receiver were too long to use. I had to get a set of shorter flat head screws, but maybe the part I received was not tapped correctly. A small amount of filing was required to properly line up the screws for the hopup. Overall, a good, simple, but very niche part.

"Awesome, product allowed me to make my one off custom. Don't over turn the hop up placement screws may strip whats there. If you don't have access to a tap, might be a tougher fix. Haven't had any issues. I used old v2 gearbox screws to affix through the four holes, so i didn't have to trim screws. Ones included were quite long. Make sure the screws are flush, or it will block the mag well and your magazine won't be seated on the hopup tube.

"Alright this thing is actually pretty cool if you look past the looks and ignore the realism. I originally got my first one to refine my stubby AK build that was a very crude build but after I got it fitted to my receiver I realized the potential this thing has. This thing is made out of aluminum and gives you the potential to run significantly lighter tactical AKs. I threw an m4 front end on my stubby AK build receiver and it was almost a pound lighter compared to my normal AK with the same length barrel. with this thing it allows you to have the perks of an AK and the weight of an m4 and you can build completely unique guns. There are some problems with this but if you're patient with it, it's pretty solid. The biggest thing is it does NOT FIT stamped steel receivers and only fits TM style milled receivers. If you don't know what you're looking for it can be tricky to find something that fits and its harder nowadays since everyone makes a stamped AK now. The easiest way to tell is if the front end is held together by 4 screws on the bottom rather than a pin and, if the AK has it, a optics rail that's screwed on rather than riveted on. next it is not a bolt on item if you have a side folding receiver. I believe it should work fine with full stock AKs but on mine I had to cut where the side folding latch goes and I had to dremel the receiver to make the hopup line up with the gearbox.

PROS:
Annoys m4 guys and AK purists
people will wonder "WTF were you thinking?!"
can make your gun really stand out and be a conversation piece
can build weird guns with this
can use the advantages from an AK (mag retention, v3 gearbox, folding stock)
can use your ak mags and loadout

CONS:
Annoys m4 guys and AK purists
people will wonder "WTF were you thinking?!"
can make your gun really stand out and be a conversation piece
incompatible with a lot of modern stamped AKs (no LCT, no stamped CYMA AKs, ect)
will most likely need work to fit
rail on top is useless bc it moves up and down easily
it's difficult to find iron sights that work (I mean its not like you're combining 2 totally different rifles together or anything)
Matrix doesn't make an m4 to AK upper receiver that will complement your cursed AK to m4 creation

after all of that I love these things and I can't wait to get my 2nd one to build a cursed VN style M16 front end with a wood stock AK receiver 100/10. (might even get a 3rd one)