2 spoked wheel layering steel thin die for hand roller mill die cut roller mills or electric roller mills (such as the Sizzix  Big Shot Switch )   Spellbinders and Sizzix etc.
 
NOTE -  Shrink with the rim on the wheel . An option is that once shrunk you can clip off the rim using wire cutters to create thin flower petal  Shrinkets beads or stamens. KEEPING THE RIM IN PLACE WHEN SHRINKING KEEPS THE PETALS FROM CURLING IN ON THEMSELVES AND FUSING WHEN SHRINKING.
The image of my passion flower shows the use of this dis cut as a stamen.  
 
size ranges from 41/8 " -3"1/8, and these will shrink to half their size.
 
Here is a link to successfully using the die cuts in a Sizzix machine.
https://vimeo.com/737292992