This is a specially heat treated steel socket-head stud with 1/2-20 threads on one end and 3/8-24 threads on the other. Used for adapting horns to boosters that do not have the same thread size.
No warranty.
Could you do us a favor? If you want something and we don't have it on the site, like a replacement for a 502 or 802 converter or 200- or 400/800-style booster, please let us know by email. Thanks!