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Strike Industries AR Enhanced Castle Nut / Extended End Plate Up to 12% Off and Blazin' Deal w/ Free S&H — 4 models

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Strike Industries AR Enhanced Castle Nut & Extended End Plate
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 3, Blue, One Size, SI-AR-TRIBUS-BLU
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 4, FDE, One Size, SI-AR-TRIBUS-FDE
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 5, Red, One Size, SI-AR-TRIBUS-RED
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
1 of 2 videos
Strike Industries TRIBUS Enhanced Castle Nut & Extended End Plate Version 2
2 of 2 videos
Strike Industries - Introducing The TRIBUS Enhanced Castle Nut & Extended End Plate
Strike Industries AR Enhanced Castle Nut & Extended End Plate
1 of 10 images
Strike Industries AR Enhanced Castle Nut & Extended End Plate
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
2 of 10 images
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 3, Blue, One Size, SI-AR-TRIBUS-BLU
3 of 10 images
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 3, Blue, One Size, SI-AR-TRIBUS-BLU
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 4, FDE, One Size, SI-AR-TRIBUS-FDE
4 of 10 images
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 4, FDE, One Size, SI-AR-TRIBUS-FDE
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 5, Red, One Size, SI-AR-TRIBUS-RED
5 of 10 images
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 5, Red, One Size, SI-AR-TRIBUS-RED
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
6 of 10 images
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
7 of 10 images
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
8 of 10 images
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
9 of 10 images
Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK
10 of 10 images
Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK

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Questions & Answers
Can it work with HK416 MR556? Manufacturer Answer

The AR Enhanced Castle nut & extended End Plate will install and work on the MR556.

by Strike Industries, Manufacturer, July 20, 2022
See 2 More Answers
Anyone else have major problems with the set screw? I’m wondering if I got either a defective part or it was used? Expert Answer

Please email us at techsales@opticsplanet.com

by Hunter, Gear Expert, January 19, 2022
View All Q&A You Have a Question? Ask!
Customer Reviews
Helpful Positive Review
Threading Warning- Great Product by Artemis Verdant, Verified Owner, June 13, 2024
First the warning to potential buyers. This product calls for specific thread length on the buffer tube. Not buffer tube length but the length of the threading on the tube where it mates with the lower receiver. This is because of the extra space the...
Read More...
11/11 found this helpful
Helpful Positive Review
Strike Industries for the win by Speedracrr6, Verified Owner, January 28, 2026
This is my second purchase of the Strike Industries Enhanced Castle Nut and in my opinion it’s the best. Not only are the QD points a great add to this, but it is super easy to install. This time I paired it with their buffer tube for the ultimate in...
Read More...
1/1 found this helpful
Helpful Positive Review
Check your buffer tube thread length by John, Verified Owner, April 7, 2024
Great upgrade for your rifle/ pistol. Make sure you know how long your castle nut threads are though. I had to get a new tube to accommodate but it was well worth the money spent. Looking to buy more for my other rifles.
2/2 found this helpful
Helpful Positive Review
Just received by jonese, Verified Owner, June 30, 2020
The castle nut is a slight different black color then the end plate, it is not coated with the same gloss look. Its more of a matte look and seems like will scratch a lot easier. I also have the Strike Ind. buffer tube in black which matches this end...
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5/8 found this helpful
Helpful Positive Review
Not fully compatible with pistol tubes by TK11069, Verified Owner, July 9, 2021
I like the red Extended End Plate. It balances the other red parts I have on this AR pistol. However, I had to use my standard Castle Nut instead of the Extended because I have a Phase 5 buffer tube and the Enhanced Castle Nut would not slide back fa...
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2/3 found this helpful
Helpful Negative Review
Good Hard Product, But... by N, Verified Owner, July 10, 2020
Be very aware, that this will remove the most forward position of your buffer tube and the stock will not fully collapse in. For a lot of folks this probably is no problem at all, but it borders on commercial grade. Be aware of this before going to p...
Read More...
9/13 found this helpful
Read All 65 Reviews

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  • Strike Industries Selector Switch, Ambidextrous, Blue, One Size, SI-AR-S-SS-BLU
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Product Info for Strike Industries AR Enhanced Castle Nut / Extended End Plate

Introducing the TRIBUS Enhanced Anti-Rotation Castle Nut & Extended End Plate. The TRIBUS is next iteration of previous AR-ECN&EEP. New features include two addition QD mounting points added to the left & right side of the extended end plate. Totaling in 3 QD mounting points. The extended end plate's QD mounts are pushed back away from the webbing of the primary hand, allowing for better weapon manipulations in tight spaced and under stress without the startling pain that can result from a pinched hand when using a sling attached to a standard, flat QD end plate. Another big improvement is the added anti-rotation castle nut feature. Once installed, use the set screw to prevent the castle nut from backing out during weapon usage. The TRIBUS is available in anodized color line.image

WARNING: California`s Proposition 65

Specifications for Strike Industries AR Enhanced Castle Nut / Extended End Plate:

Manufacturer: Strike Industries
Gun Make: AR Platform
Quantity: 1
Condition: New
Gun Type: Rifle

Features of Strike Industries AR Enhanced Castle Nut / Extended End Plate

  • Antiroation Castle Nut
  • 3 QD Mounting Points
  • Extended End Plate for prevention of pinching hand when using a sling attached
  • Staking not required, castle nut winot back out once screw is threaded.

Package Contents:

  • Strike Industries AR Enhanced Castle Nut / Extended End Plate
  • 1X Extended Castle Nut
  • 1X Extended End Plate
  • 2X M3X12Mm Set Screw
  • 1X1.5Mm Hex Key
  • 1X Warning Card

Strike Industries AR Enhanced Castle Nut / Extended End Plate Orderable Models

List of Orderable Models

  • Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK , MPN: SI-AR-TRIBUS-BK , UPC: 708747548457 , Code: 3Q-CAN-STR219-SI-AR-TRIBUS-BK
  • Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 3, Blue, One Size, SI-AR-TRIBUS-BLU , MPN: SI-AR-TRIBUS-BLU , UPC: 708747548617 , Code: 3Q-CAN-STR219-SI-AR-TRIBUS-BLU
  • Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 4, FDE, One Size, SI-AR-TRIBUS-FDE , MPN: SI-AR-TRIBUS-FDE , UPC: 708747548624 , Code: 3Q-CAN-STR219-SI-AR-TRIBUS-FDE
  • Strike Industries AR Enhanced Castle Nut / Extended End Plate, Version 5, Red, One Size, SI-AR-TRIBUS-RED , MPN: SI-AR-TRIBUS-RED , UPC: 708747548631 , Code: 3Q-CAN-STR219-SI-AR-TRIBUS-RED

Strike Industries AR Enhanced Castle Nut / Extended End Plate Unavailable & Discontinued Models

List of Unorderable Models

  • USED Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK, EDEMO13, Condition Fair, Installed/Mounted , MPN: SI-AR-TRIBUS-BK-EDEMO13 , Code: 3Q-CAN-STR219-SI-AR-TRIBUS-BK-EDEMO-IN-D
  • USED Strike Industries AR Enhanced Castle Nut & Extended End Plate, Version 2, Black, One Size, SI-AR-TRIBUS-BK, EDEMO12, Used, Condition Fair , MPN: SI-AR-TRIBUS-BK-EDEMO12 , Code: 3Q-CAN-STR219-SI-AR-TRIBUS-BK-EDEMO12
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Last updated 2026-07-16 UTC.