3M™ Diamond Grade™ Truck Conspicuity Markings 983 are microprismatic retroreflective conspicuity markings designed to mark the emergency exits, sides, and rear of large trucks and tractor trailers for enhanced visibility and detection on the road. Featuring prismatic lens technology, these markings are engineered to provide good visibility at high and wide entrance angles. These markings are available in a variety of colours and configurations designed to meet industry standards. Conspicuity markings with a custom logo are available for regulated vehicles.