B5 Systems SRK Extension Kit Stock Extension – AR-15/M4

The B5 Systems SRK Extension Kit provides additional length-of-pull adjustment for shooters who need more reach on their AR-15 or M4 platform. This extension adds approximately 0.75 inches to your existing B5 SOPMOD or Enhanced SOPMOD stock, improving cheek weld consistency and shoulder fit for larger-framed shooters or when wearing body armor or heavy outerwear.

Machined from reinforced polymer and finished in matte black, the SRK Extension Kit installs directly onto compatible B5 Systems stocks without permanent modification. The extension integrates seamlessly with the stock's original lines while maintaining full adjustability of the carbine buffer tube positions. Installation requires no gunsmithing—simply remove the buttpad, attach the extension, and reinstall.

• Type: Stock Length Extension
• Compatible Firearms: AR-15/M4 with B5 Systems SOPMOD or Enhanced SOPMOD stocks
• Material: Reinforced polymer
• Finish: Matte black
• Added Length: Approximately 0.75"
• Installation: Drop-in, no gunsmithing required