Saturn V Launch Vehicle Third-Stage Exploding Bridge Wire (EBW) Firing Unit, with the main box measuring 6.5" x 3.5" x 3; a longer black cable is attached. Mounted on a 20" x 8" plywood board with edges wrapped in electrical tape. The side of the unit features a NASA Property/Douglas Aircraft Co. label, reading: "Nomen. Firing Unit, P/N 40M39515-119, Ser. No. 574, Contract NAS7-101." The top bears a General Laboratory Associates label and the other side has an undated "2nd Test" inspection tag. When commanded by the on-ground Range Safety Officer, the EBW would initiate explosive charges to destruct the stage in the event that the Saturn V deviated from its nominal trajectory during launch.