This cable is "used to detonate the charges in atomic bombs. It's perfectly legal to own these. They're relics from the atomic bomb development at Los Alamos National Laboratory." Only $5 at the Black Hole shop, in Los Alamos, NM.
That's the kind of material you can get at the Black Hole, a military surplus store that has all kinds of material from the Manhattan Project era, from those cables to old school scientific calculators.
I'd have loved to meet the founder, Ed Grothus: