Item 47.
"Item 47" is a discarded Chitauri gun from Loki's war with the Avengers.
History[]
"Item 47", as it is known to S.H.I.E.L.D., was discarded when the Chitauri were defeated by the Avengers. Benny and Claire, a down-on-their-luck couple, soon found the gun. Aware of what it could do, they decided to rob some banks with it.