These are black and white brochures with text about the origin and history of the Canyon Diablo impact crater. The brochures have 3-4 printed pages and one has a black and white photo of the crater. These brochures are undated, and likely originate from the 1960's to late 1970's, judging from the logo, printing style, and aging of the paper.
Refer to the photo. The black centimeter cube is shown for scale and is not included. You are purchasing two (2) brochures shown.