The DDM4v3 Carbine by Daniel Defense carries a 100% satisfactions guarantee against defects in original materials and workmanship. If your DDM4v3 shows evidence of such defects, Daniel Defense will make every accommodation to fix, repair, or replace your firearm in the most expeditious and inexpensive manner possible. Daniel Defense does not warranty products or damage caused to our products by the correct or incorrect installation of other manufacturer's products. Be sure to retain your sales slip as proof of purchase date when making a claim.