Products warranty period: 14-16 months from the date of purchase. DC ballast we offer 14monhts warranty, AC ballast we offer 16 months warranty. Exclusions: Defects that are not caused by the quality of merchandise,Improper installation, misuse, vehicle crash, acts of nature, etc. Replacement Procedure: Step one:Customer send us the photo of defective merchandise. Step two:Ordinarily check by our technology worker. Step three: Right now we have achieved ALL ballast 100% replaced to customers based on the photo which show us clear manufacture code and wire cutting Step Four: we send you the warranty goods by free of charges, but the shipping fee pay by buyer