I wear size small.  Many sports bra styles don't come in small sizes.  I bought this one because it came in my size, and because it has the front zip feature (I really hate struggling with the hooks in the back of other bras).  The zipper is sturdy and zips up easily.  The bra works well for me for running and other exercise.  I will definitely buy this again in the future.  It is now my favorite sports bra.