i have a purchased one- it is (2) 6" mirrors
with a (spine) available in many quilt shops, places like clotilde's, keepsake quilting, nancy's notions, hobby lobby, joannes,
or you can easily make your own- purchase 2 square mirrors, use a number of layers of masking tape on the back aligning the two mirrors. so they fold together *facing each other* or open when needed. (duct tape works pretty good for this too.