Item 47 is a Chitauri weapon found by Benny Pollack and Claire Wise. All the weapons after the invasion deactivated and could not be reactivated until Benny got a hold of one and managed to reactivate it.
Then the couple decided to use it to successfully rob banks until got caught by Sitwell. Interested of Benny's ability to re-activate the Chitauri weapon, Sitwell inducted the couple into S.H.I.E.L.D. as special agents.