andheld welding: SUP15S focusing mirror replacement method本文阐述了SUP15S聚焦镜的更换方法（2020款）This article explains the replacement method of SUP15S focusing mirror (2020 model)注意：更换时保持环境无污染，尽量在早上或晚上无人工作时更换Note: Keep the environment free of pollution when replacing, and try to replace it in the morning or eve
