Commonly found in older cars. 50's, 60's, 70's, & some 80's for attaching tonneau covers, boots, convertible tops also found on some sports cars and foreign cars. 8-32 machine thread. 1/2" long, snap diameter is 3/8" overall length is 3/4". This does not include the top snaps, or nuts. If you need the top snap caps, or nuts, or hand held snap tool.....let me know I can combine a kit for you. Thanks!