The HK Buffer Retainer Pin is a genuine factory component designed specifically for MR556A1 and HK416 rifle platforms ensuring proper buffer system function and reliability.HK Buffer Retainer Pin (Part for MR556A1 & HK416)SKU: 50986544 UPC: 642230249332Genuine HK factory componentCompatible with MR556A1 and HK416 rifle systemsEssential for proper buffer tube assembly and functionThis precision-manufactured pin is critical for maintaining the integrity of your HK rifle's buffer system ensuring reliable cycling and optimal performance during operation.