All of our product are produced in strict quality control system, the defective rate is less than 0.2% according to our shipment records. We offer 5 years warranty for this product, if there is any defective during the warranty, please provide the picture or video for the working situation of the defective lights, we will ship the new lights to you within a few days or send it together with your next order. We have a professional team which is in charge of after-sales service,also a service hot-line dealing with your complains and feedback.