$249.95 - $359.95
Calculated at Checkout
Fits: MP5 .22LR Caliber only
  • Rear .22 cal-specific adapter included
  • MJF/6061 aluminum Hybrid adapter construction
  • Modular design for individual personalization
  • Folds left or right by simply reversing the hinge
  • Offset extension mounts in 4 different configurations
  • Uses our 7.75" extension for a 13-7/16" Length of pull (LOP)
  • Can be configured for the A3 Tactical Steady-brace or Tailhook brace

The A3 Tactical Modular Folding Brace (MFB) is a great addition to your .22 caliber HK MP5. The MFB is designed to provide modularity in style, form, and function.  Various configurations are available to personalize the setup, and the modular system components can easily be configured to suit each users unique preferences. With multiple brace options, 2 different extension arms, and the ability to fold right or left, the user has 40 possible variations that can be configured by simply removing a few screws and changing up the configuration.

REAR ADAPTER: Manufactured as a Polymer/Aluminum hybrid, our rear adapter provides the OE fit of the polymer adapter with a heavy duty 1/4" thick aluminum insert to reinforce the mount for the stock or brace. Completely unique in design, this adapter provides improved stability by covering more surface area of the receiver. 
HINGE: Our proprietary hinge is machined from 6061 aluminum and can be mounted in the standard configuration to fold left, or upside down to fold right. The hinge utilizes a positive spring-lock for both the open and closed position, allowing the user to simply and quickly release the brace from either position by simply pushing a button.

EXTENSION ARMS: Our extension arms are available in both straight or offset configurations. Straight extensions simply extend rearward, positioning the brace end in line with the hinge point. Offset extensions offset one end 1.25" from center. Each end is symmetrical, allowing the user to mount it in 4 different positions as shown to the right. These offsets can be used to clear objects such as an ejection port or charging handle, raise/lower a cheek weld for different height optics, or position the brace end higher or lower to suit your shooting preference. 


All extension arms incorporate M-LOK slots along the full length of the arm. This allows the user to mount a QD (Quick-disconnect) sling mount anywhere on the extension, or any other M-LOK accessory.

BRACE OPTIONS:With our modular design, the user has their choice of A3 Tactical Steady-brace (in Polymer or Aluminum), or the Gearhead Works Tailhook (MOD1 or MOD1C). 

CHEEK RESTS: We have 2 different cheek rests available for the HK folders - the clamp-on, non-adjustable cheek rest, or our XENO Modular cheek rest. The clamp-on is a fixed-height polymer rest measuring 4" long that raises the cheek rest 1/2". The Xeno Modular Rest can raise the cheek rest 5/8", 7/8", or 1-1/8". The XENO mounts via M-LOK and also has an offset that allows the cheek rest to be positioned 1" offset of the mount, if necessary. The XENO has an aluminum mount with injection-molded Polymer spacers and cheek rest.



NFA BRACE DISCLAIMER: The A3 Modular Brace is not designed nor should it be used as a stock or to discharge a firearm from the shoulder. The A3 Modular Brace is to be used as a pistol stabilizing arm brace. You are responsible for the proper and legal use of the A3 Modular Brace at all times. If you have purchased an A3 Modular Brace and wish to utilize the modularity function with parts designed for our Modular Stock, please be aware of all federal, state and local laws and ordinances that you must obey. The National Firearms Act regulates items such as short barreled rifles, and by utilizing components of the A3 Tactical Modular Brace as a firearm stock, you may be subjecting your firearm and yourself to NFA laws and regulations. It is your responsibility to obey all laws and properly register any NFA items you may create with use of A3 Tactical products.

Related Products