Class 3B Visible/Invisible Plastic Sign - ANSI Z136.1 indicates that laser area warning signs should be posted around Class 2M and 3R laser areas and is required to be posted around all Class 3B and 4 laser areas. Additionally, NOTICE signs are required for Class 3B and Class 4 lasers during maintenance, servicing, and similar situations. LIA has a laser area warning sign for any type of laser. LIA signs are 10" x 14" in size are are available in plastic only. All signs meet the ANSI Z136.1 requirement for laser safety.