This is a fondant rose cutter I made for my mom.
The usage is very straightforward(theres an instructional video below these instructions) just cut out a piece of fondant, fold it in half along the length of the cutout and roll it. After rolling it fold out the leaves and pinch the base, voilà, you've got yourself a neat little fondant rose.
https://youtu.be/crbvOtAD76g
This part comes in one size, if you want me to upload other sizes or if you have specific requests let me know in the comments!
This design is also available on Thingiverse:
http://www.thingiverse.com/thing:2292812