Buffer Retainer Pin and Spring

Are you sure?

I agree all barrel/upper/bolt purchases are final. I understand that this is a GEN2 product and that GEN1 and GEN2 products are not compatible with one another. I have verified my serial# and I have already purchased and installed items that have upgraded my FX-9 from a GEN1 to a GEN2 and wish to purchase this additional GEN2 item.