These 19 millimeter dice have come directly from the floor of premier Nevada casinos. They have a circular marking on the 4 to ensure they are not used in the casino again. Each pair of precision dice will have matching serial numbers, razor edges, and the logo from a Nevada casino. Precision casino dice are manufactured from high-quality plastic material that is free from defects. The spots on their faces are made flush to ensure there is no imbalance to the dice. The razor edge(straight sharp edges) ensures that the roll will be more random than that of dice with rounded corners. The matching serial numbers ensure similar play time and guarantee authenticity. You will receive 2 matching casino dice from a random Nevada Casino.