Dritz85 Sew-On Snaps, Clear, 5/16-Inch 12-Count

What are the dimensions of the snaps in either millimeters or inches?? The size # doesn't mean much to the uninitiated.

This may be a dumb question, but do these have the front part of the snap? It doesnt look like they are pictured...

Dumb Question -- These look like the "male" (not sure what's its called) part of the snaps. Do I need the "female" part for it to work as a set?

How large are these snaps - about 3/4 of an inch?