The image shows a rectangular metal plaque with the text "Cambridge Museum Centenary of the Centenary Exhibition" engraved on it. The plaque is placed on a concrete surface with a small metal handle on the top right corner. The handle appears to be made of metal and has a curved shape with a pointed end. Below the handle, there is a smaller metal plate with the same text engraved on the bottom right corner that reads "Not to be opened prior to 1st April 21st". The plate is rectangular in shape and has two small holes on either side. The text is engraved in black ink and is clearly visible.