Sylvan Arms

Premium Quality and Affordability


AR15 & AR9 Folding Stock Adapter Gen. 4

(5 customer reviews)


The direction of the fold is orientated to the direction as if your build was pointed down range. On a standard build, Folding to the RIGHT folds toward the ejection port. Folding to the LEFT folds off to the side with out the ejection port. Our previous folders have folded off to the LEFT.

The Sylvan Arms Folding Stock Adapter allows you to fold your stock and significantly reduce the length of your rifle for easy stow and travel.

The Gen 4 AR Folding Adapter sits closer to your AR lower to reduce the length and any gaps. Turn your rifle into a foldable AR providing a compact rifle setup.


  • Now Available as a left or right fold, pick the best AR side folder setup to fit your needs.
  • Compatible with most AR15s and some AR9s or AR10s. (Some AR9 BCGs are not compatible.)
  • Standard 1-3/16” x 16 thread and does not require any additional parts to be used with standard AR15 Bolt Carrier Groups.
  • Compatible with JP Enterprise Silent Capture Buffer Spring right out of the box.
  • CNC-machined in the USA from 7075 Billet Aluminum, making it uniquely lightweight and corrosion-resistant. This assembly weighs only 6.0 ounces.
  • The included wrench makes for a quick and easy install. The product does not need to be disassembled in order to install it onto your rifle/pistol.

Simply screw on, fold and carry!

Product Details

  • Includes a .625 Aluminum Bolt Extension compatible with the JP silent capture spring
  • Includes a castle nut wrench
  • Fit: Platforms .223/5.56 to .308 & Most 9mm
  • Does NOT work with Tippmann 22 or LWRC Pistols
  • Some 9mm bolt carriers with standard sizing, 5/8 ID (.625) can use the included bolt extension after removing the pin and weight from the back of the BCG
  • Now Compatible with Silent Capture Buffer Springs. (Does NOT work with Armaspec Silent Capture)
  • Compatible with your 300 Blackout AR’s for an effortless 300 Blackout Folding Stock Setup.
  • If your bolt carrier group is causing the bolt extension to come up short contact us for a conversion. (Currently unavailable)
  • Includes all items needed to install.

Installs in minutes, Brandon will guide you on the Gen 4 AR15 Folding Stock Adapter Install.

Direction of fold

Adapter Opens To The Left, Adapter Opens To The Right

5 reviews for AR15 & AR9 Folding Stock Adapter Gen. 4

  1. Daniel Lederman (verified owner)

    Really impressed with the new model. It’s 2.5 ounces lighter than my law tactical and the same size. It very well on my
    Lower and locks fully. Great warranty as well. I’m Very satisfied with it

  2. brandongeil214 (verified owner)

    Good quality easy install and cycled every round.

  3. Brandon (verified owner)

    Bought this for a pistol build, have used the more expensive options on other and comparably this if we’re being honest is a little nicer in my opinion. 100% reccomend buying this and their customer service is awesome.

  4. Marksman

    Very satisfied with the quality of this folder highly recommend!
    very satisfied with the bolt safe in the back of folder when folded,
    in case of round in chamber and the need to self defend.
    I have both Gen 3 and 4 they are one of my favorite attachments!
    Customer service, huge shoutout thank you for helping me with my lost package!

  5. D. Tisdale (verified owner)

    First let me say that the customer service I received from MB / sylvan arms was absolutely impeccable and an actual pleasurable and satisfying experience. Now with that out of the way, I received my gen 4 folding stock adapter and I was super excited to get it installed on my ar. Being the rookie that I am with gunsmithing, I figured that this would be an easy first time gunsmithing project. Even though the instructional video was very detailed, a lil fast but , detailed. I missed a step and I really screwed up the install. Completely screwing up the adapter. I called to see what I needed or could do to fix my mistake. I was told to send it back and they would fix it for me. Well after about 3 days I received an email stating that I had messed it up so bad that they could not fix it and they would just send me a replacement. This type of customer service is absolutely the thing that will make me come back to sylvan arms for anything I may need for my future ar builds and needs.

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