All products we sell are in good quality and under strict examination before they are shipped. We will try our best to avoid any quality problem. We provide 2 or 3 years warranty. Within the warranty period, we'll be responsible for repair or replacement of any defected or damaged products free of charge. And for whole service lifetime, we'll be responsible for repair or maintenance with only charge of the replacing components cost. The damage by human action or force majeure shall be not within the warranty scope.