Acrobat Add crop marks

[nrod2012]

I created a droplet that crops PDFs using Preflight /Single Fixups/ Set CropBox to TrimBox which in reality it is hidding the boxes. Now, I  need to create another droplet to show the crop marks again but I can't find a fixup that show the crop marks again. Any suggestions?

[Luke Jennings3]

Set cropbox to media box? You will need to duplicate an existing preflight (from the fly-out menu) in order to edit it and create this new preflight.