Works much like a rivet nut but instead of female threads, offers a male threaded stud that you can hang from and tighten down attatchments on. Includes 5 each of 5/8"L threaded rivet studs: M5, M6, M8, 10-24, 1/4"-20 & 5/16"-18. Great for firewall mounting, exhaust hanging, and tons of repairs.