• Two additional QD mounting point added to the left and right side compared to the previous enhanced castle nut & end plate
  • Features a total of 3 QD mounting points, center, left and right side
  • Upgraded version added groove for easier installation of takedown pin detent spring
  • Features a anti-walk castle nut set screw
  • Easy drop in installation
  • Simplified installation of takedown pin detent via a set screw
  • Available in Black, Flat Dark Earth, Blue, and Red finish!


  • Material:
    • Enhanced Castle Nut: Steel
    • Extended QD End Plate: 6061-T6 Aluminum
  • Finish: Hard Anodized
  • Weight:
    • Enhanced Castle Nut: 0.90 oz.
    • Extended QD End Plate: 1.34 oz.

*Due to various factors that occur during the anodization process, the color may differ between batches for this product.


  • Carbine buffer tubes

*Fully collapsed position on buffer tube will be lost due to the extended length of the Enhanced Castle Nut

*Minimum thread length on receiver extension/buffer tube of 30mm (1.18") is required

*Torque: Do not exceed 35 ft/lbs (47.45 nM) for the castle nut


  • 1x Strike Industries TRIBUS Enhanced Castle Nut
  • 1x Strike Industries Extended QD End Plate
  • 1x Set Screw
  • 1x Allen Wrench

Strike Industries TRIBUS Enhanced Castle Nut and Extended QD End Plate


The great thing about the AR-15 platform is that it is easy to customize, upgrade, and personalize all of its components to make the weapon truly yours. The Strike Industries TRIBUS Enhanced Castle Nut and Extended End Plate are two of these upgrades that add striking aesthetics to your weapon while also improving your functionality and comfort.

Why Upgrade Your AR-15's Castle Nut?

The standard AR-15 castle nut's function is to hold the buffer tube to the lower receiver, and it accomplishes this just fine. However, the Strike Industries castle nut is not just your standard castle nut. The extended teeth give your AR-15 a fresh new modern look, and the extended QD end plate comes in four different colors so you can customize your AR to your preferred look. More than just aesthetics, the extended QD end plate serves to improve your shooting experience by giving you added control and comfort.

Improved Function with TRIBIUS Enhanced Castle Nut and Extended End Plate

The Strike Industries' latest version of the TRIBUS Enhanced Castle Nut and Extended End Plate give you the three different QD mounting options of center, left, and right to attach your sling. The benefit to the extended end plate is that it moves the QD sling mounting point away from the webbing of your hand and therefore prevents the sling from pinching your skin. This is a common problem with the standard AR-15. It does not matter if you are left or right-hand dominant this Strike Industries castle nut and extended end plate will improve the control and function of your weapon.

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