In principle, we provide "A one-year warranty on the products after delivery". However, in some cases, the respective service lives of our products are different according to the mounting environment including ambient temperature, humidity, amounts of dust. Also, the service lives supposedly depends on many factors like the surge current flow by the load or the frequency of the short circuit. At present, one of our regular customers regularly uses our power supply under the harsh condition of mounting environment leading to limit the service life within a year or so, and they repeatedly purchase the power supply which is considered as consumable. In the meanwhile, another customer has continuously used the same product for more than a decade.