3M™ Diamond Grade™ Conspicuity Markings Series 983 are highly retroreflective micro-prismatic markings designed to mark the emergency exits, sides and rear of vehicles for enhanced visibility and detection. They are available in a variety of colours and configurations.3M Diamond Grade Conspicuity Markings Series 983 are highly retroreflective micro-prismatic markings designed to mark the emergency exits, sides and rear of vehicles for enhanced visibility and detection. The reflective marking consists of prismatic lenses that are formed in a transparent, synthetic resin, sealed and backed with a pressure-sensitive adhesive and clear poly liner. These markings are available in a variety of colours and configurations to meet general and Industry specific requirements such as DOT (truck trailer), FRA (railcar), NFPA1901 (emergency vehicle ), FMVSS and CSA D250 (school bus).