Had someone offer me one in trade and it seemed a little fishy...

K thanks guys

I wouldn't have one anywhere near my AR

A DIAS is considered a "machine gun" under the National Firearms Act.  A number were made in the late 70's and early 80's until BATF classified them as a MG. Those made before November, 1981, were grandfathered in that they were not subject to the ATFs ruling. BUT, if in conjunction with other full auto parts and a lower it would still constitute a machine gun. The problem is there is really no way to tell when it was manufactured. The only safe DIAS to have is one that was legally registered prior to May 20, 1986, and they cost around $10,000. Same transfer procedures as for a machine gun.