The much-anticipated movie Oppenheimer by Christopher Nolan is nearly three hours long and has an R grade from the Motion Picture Association.

This is the first Nolan movie since 2002 to get an R grade. The R grade means that the movie has some content that is not appropriate for kids.

The movie starring Cillian Murphy, is about how the atomic bomb was made during World War II and how it affected the man who made it, Robert Oppenheimer, on an emotional level. Murphy plays the main role in the story.

Robert Downey Jr., Matt Damon, Florence Pugh, Emily Blunt, Kenneth Branagh, Rami Malek, Casey Affleck, Gary Oldman, James Remar, Josh Hartnett, and Alden Ehrenreich are all in the movie, which has a lot of famous people in it. The maker of Oppenheimer says that there are also scientists in the movie as extras.

Christopher Nolan told the AP that Oppenheimer is shot in both IMAX and film and that “11 miles of film stock” are used.

The director said, “The sharpness and the clarity and the depth of the image is unparalleled. The headline, for me, is by shooting on IMAX 70mm film, you’re really letting the screen disappear. You’re getting a feeling of 3D without the glasses. You’ve got a huge screen, and you’re filling the peripheral vision of the audience. You’re immersing them in the world of the film.”

Oppenheimer and Greta Gerwig’s Barbie will both be in theaters on July 21.