RFH 355nm UV laser marking mask date without carbonization Mask marking: RFH 355nm ultraviolet laser, fast speed and high precision Mask date marking, need to use UV laser cold light source   RFH has been working for 13 years. The 355nm UV laser specially designed for mask marking has fast speed, high accuracy and high stability. It is a dark horse in the plastic marking industry and should not be missed.   For medical masks and civilian masks, we can first distinguish them from the outer packaging of the masks.   Take a look at the product name. The product name on the outer packaging of medical masks must have the word "medical".