DoubleStar Corp FSM-AR Folding Mechanism for AR Type Stocks with Boss

Manufactured by DoubleStar Corporation
SKU: A504-K
MPN: A504-K
Manufactured by DoubleStar Corporation
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The DoubleStar Folding Stock Mechanism for AR style stocks (FSM-AR) attaches between the receiver block and stock on your AK platform rifle and allows you to attach an AR stock with folding functionality. The machined Boss increases rigidity. This model is compatible with both fixed and collapsible stocks and only folds to the left.

Note: This model with Boss requires a receiver block. Will not work on AR-15 rifles.

  • Folding stock adapter for AR pattern stocks
  • With Boss
  • Machined from 7075-T6 aluminum
  • Hardcoat anodized
  • Left side folding only

The DoubleStar Corporation started out as a retailer selling AR-15 parts and Accessories. Soon they began designing and manufacturing their own parts and accessories and eventually moved on to full weapon systems. Located in Kentucky, DoubleStar is dedicated to building rifles with US made parts only, so you know that what you receive is high quality.
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BrandDoubleStar Corporation
TypeStock Adapter
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to

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