These are surplus UZI bolts that have been clearanced to clear the semi auto UZI barrel restrictor ring. They are for a full sized 9mm UZI sub machine gun with semi auto barrel restrictor rings. They are NOT slotted to clear the semi auto blocking bar. These Uzi bolts do not come with the extractor, extractor retaining pin or the recoil spring assembly. They will work in any full sized Uzi SMG without a blocking bar.