I bought these over a year ago at a local auction of an RCA engineer’s estate. This guy worked on several Apollo missions and specifically designed the cameras used on the missions. In his estate were a couple of copies of this photo flip book showing the lunar lander taking off from the moon. The books were published by RCA in 1971. When you flip through the 21 pages, you see the lunar lander taking off. There weren’t many of these books created and they are scarce. The booklets measure 3.5” x 2.5”.