NASA Photo ID: KSC-72C-0255
Date Taken: 03/31/72
Apollo 16 mission commander John W. Young appears to be stowing an item in his spacesuit during pressure checks prior to participating in the space vehicle countdown demonstration test today with commander module pilot Thomas K. Mattingly II, center couch, and lunar module pilot Charles M. Duke, Jr., seated in the rear.
Source: http://images.ksc.nasa.gov