Button provided to the audience after the performance of Part 2 of the Harry Potter And The Cursed Child play. #KeepTheSecrets requests that fans not reveal what happens in the plot as to not ruin the performance for others. The hashtag started trending shortly after the first preview in June of 2016 in London and has continued for all new touring city performances.
This button has part of the Cursed Child playright book design of the right Snitch wing with the #KeepTheSecrets above it on a yellow/goldenrod background. It has a safety pin type attachement on the back and is approximately 1.5 inches round.
The right Snitch wing was provided when exiting the theatre for Part 2 of the London play.
London released this design as well as another button with the left Snitch wing for Part 1. Other cities, like New York, released a different design with both wings as the play is only 1 part in other cities.