A regular jean uses 4 fly buttons, while a low-rise jean uses 3.
This is the SMALLER button used on the fly of a traditional button-fly jean. Note that the top (waistband) button on a pair of jeans is larger than this button; and in a different listing.
Guide for attaching with common tools (copy the URL into a new browser tap):
imgur.com/a/I4wv5UI
** If the imgur.com images aren't showing up, copy this URL into a new tab:
imgur.com/beta/disable
Imgur is experimenting with a new version of their site? and it doesn't work on every browser. So this link returns you to the original version (that works everywhere).
Button Width = 13.4 mm (17/32 in)
Button Stem Length = 3.1 mm (1/8 in)
Tack Width = 9.5 mm (3/8 in)