The image is a blue sign with Japanese text and an image of a Sakae 31 Ko-Type Engine Serial No. 31707. The sign is located in a museum or exhibition space with other exhibits visible in the background. The text on the sign is written in both English and Japanese, and it appears to be explaining the engine's specifications. The image shows the engine in detail, with various components such as the pistons, valves, and other mechanical components visible.