Commonly found in older cars. 50's - 60's 70's for attaching tonneau covers, boots, some convertible tops also found on some sports cars and foreign cars. 10-32 machine thread. 5/8" long. Diameter of Snap Head is 3/8" across.
These include the top snaps the Caps and Sockets, & Nylon Locking Nuts. If you should need something else Just let me know.
Thanks!