This is the factory Heckler & Koch takedown pin spring for the HK416, also listed for the MR556A1. It provides detent tension for the takedown pin. Replace a weak or lost spring to keep the pin from walking. Compare it with your existing part or the manufacturer's parts diagram to confirm it matches your firearm before ordering.
- Part: Takedown pin spring
- Fits: HK416 / MR556A1
- Brand: Heckler & Koch
- UPC: 642230248021
