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Questions & Answers
Is this mil spec or commercial? Expert Answer

Fab Defense does not state if the buffer tube is Mil-Spec or Commercial on the Fab Defense M4 Folding Buttstock for MP5. I recommend contacting Fab Defense for that information.

by Hunter, Gear Expert, May 26, 2023
Will this work with a ptr 9ct? Manufacturer Answer

Im not sure. if the ptr is exactly the same as a MP5 then it will fit

by FAB Defense, Manufacturer, July 16, 2025
Customer Reviews
Helpful Positive Review
Fits MP5 perfectly. by Donald, Verified Owner, November 22, 2023
Fit my mp5 with no modification. Doesn't actually match the photo but it's a great stock.
1/2 found this helpful
Helpful Negative Review
Doesn't fit right by Fred, Verified Owner, December 16, 2021
I'm having to cut pieces, shave pieces and hone pieces just to make it fit my gsg-522. Unless you have ALOT of patience don't do it. Wish I would have sent it back before I tried to modify so it would fit
1/12 found this helpful
Read All 2 Reviews
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Product Info for Fab Defense M4 Folding Buttstock for MP5

The M4-MP5-FK Folding and Collapsible Buttstock for the Heckler & Koch MP5 provides you with upgraded tactical versatility.image

Specifications for Fab Defense M4 Folding Buttstock for MP5:

Manufacturer: FAB Defense
Color: Black
Gun Model: AR-15
Gun Type: Rifle

Features:

  • Rock solid One Piece Ergonomic Design
  • Special Non-Slip Texture
  • Provides Optimal Eye to Target Alignment
  • Made from Reinforced Composite Materials
  • Permits Appropriate Clearance for Trigger Access when in Folded Position
  • Integrated Quick Detach Sling Swivel Connectors on Both Sides
  • Enhances Natural Fighting Stance and Hold on your MP5
  • Rubber Butt Plate for Reducing Recoil and Slipping
  • Locking is Released by the Push of a Button
  • Slightly Angled to Allow Optimal Sight Alignment
  • Spring lock on Folded Position
  • Opens by a Simple Pulling Motion and Locks
  • No Gunsmithing Required
  • Provides Storage Compartment for Batteries
  • Width 1.85in. Height 5.1in. Length 9.96in.
  • Height (open/deployed) 12.99in

Package Contents:

  • Fab Defense M4 Folding Buttstock for MP5

Fab Defense M4 Folding Buttstock for MP5 Orderable Models

List of Orderable Models

  • Open Box, Dealer Demo, FAB Defense M4 Folding Buttstock for MP5, Black, FX-M4MP5 , MPN: FX-M4MP5-DMO , Code: 1S0-BSC-M4-MP5-FK-FX-M4MP5-DMO-OB-A
  • FAB Defense M4 Folding Buttstock for MP5, Black, FX-M4MP5 , MPN: fx-m4mp5 , UPC: 7290105941893 , Code: 1S0-BSC-M4-MP5-FK-FX-M4MP5
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