This is the factory Heckler & Koch buffer retainer pin for the HK416, also listed for the MR556A1. It holds the buffer retainer in the lower receiver. A small part worth keeping on hand as a spare. Compare it with your existing part or the manufacturer's parts diagram to confirm it matches your firearm before ordering.
- Part: Buffer retainer pin
- Fits: HK416 / MR556A1
- Brand: Heckler & Koch
- UPC: 642230249332
