• Set screw to retain takedown pin and detent for ease of installation
  • No peening or staking needed with the Anti-Rotation Castle Nut/End Plate design
  • Anti-rotate QD socket
  • Multiple sling attachment points


  • Material: Steel
  • Finish: Black
  • Weight:
    • Multi-Function Endplate: 0.71 oz.
    • Anti-Rotation Castle Nut: 0.63 oz.


  • AR-15 and AR-10


  • 1x Multi-Function Endplate
  • 1x Anti-Rotation Castle Nut
  • 1x Detent Set Screw
  • 1x Anti-Rotation Set Screw



How many times have you heard this: “Well, that’s the way we’ve always done it.”? It doesn’t matter where it is, that’s dangerous talk. When you’re talking about a subject as dynamic and progressive as tactical firearms, it’s downright restrictive, antique thinking. Something as seemingly simple as the traditional installation and peening of the AR 15 castle nut bogs down progress. In order to free the armorer who wants to rebuild rifles, or swap out parts as better choices come to market, Strike Industries has developed the SI Anti-Rotation Castle Nut (ACN) and Multi-Function End Plate (MFEP.)

A Simple Idea Opens Doors for You

Strike Industries was built on supplying the small arms community with superior versions of products that other manufacturers don’t bother with. Their Anti-Rotation AR 15 Castle Nut and Multi-Function AR End Plate Set features a detent set screw and anti-rotation set screw to secure your system rather than using the old way of securing the receiver extension by peening or staking. The result is added flexibility you might never have thought about before but will enjoy when it comes time to replace worn parts or try something new. You’ll no longer hesitate to do something just because it’s a pain in the neck to disassemble.

Be Flexible, Stay Ahead

You want every edge you can get. Now, you can easily stay an extra step ahead with the freedom and flexibility brought to you by the Strike Industries Anti-Rotation Castle Nut and Multi-Function End Plate.
The Multi-Function AR End Plate (MFEP) allows you to choose your preferred sling type. Whether you use a hook and loop, traditional sling loop or you need a quick detach socket, they’re all here. You’re not married to one or another and you can change as often as you like without changing the end plate. Add this to the easy removal of the Anti-Rotation Castle Nut and your AR system is now an ultra-flexible weapon system that you can retool for whatever the future holds. Stay ahead of the competition, and Strike First.

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