That is standard issue with the new HK416A5 and HK417A2. It works in concert with the A5 pistol grip and its base to tuck neatly inside. The tools are all common for use with those weapons.Erm...
This one: Heckler & Koch G28 BW Universalwerkzeug für V7 / V4 Griffstück German GunWorks
Kinda curious what the socket end is about.
Says right in the link you provided - "Nut screw for handguard"Erm...
This one: Heckler & Koch G28 BW Universalwerkzeug für V7 / V4 Griffstück German GunWorks
Kinda curious what the socket end is about.