These are fully vector buttons made in flash. So, you can stretch them as much as you want without loosing quality.
NOTE: I have put the jpeg images instead of vectors in preview file to protect the preview.
All the buttons are placed on the stage. To use, just drag and drop any button into your FLA files. To see how to assign a click function to a button… an example is given in the FLA file’s action script, on the first layer.