Here's a nice option for those of you with a Uneekor QED simulator or a GSA simulator requiring a specially marked ball.   Put these specially prepared decals on a tour quality ball instead of using the rocks that come with the simulator.   Work great.   I use 5-6 decals per ball.   $40 per sheet of 100 decals.  Included are instructions about how to cut them out and for proper placement technique.   Watch this video to understand the application process!:   https://www.dropbox.com/s/ntfrhpyqfdnztnn/IMG_7279_Merge%281%29.mp4?dl=1