Thanks for help, I have used google a lot and yes it's a 12 pt str bit but it's difficult finding 28mm , but I will try moreThat is the influence of VW/Audi ownership of Ducati.
12pt star bit (Otherwise known as Triple Square Bit). Not sure what size that is but search "triple square bit" on Amazon.com. There is 10piece set (4/5/6/8/9/10/12/16/18mm), $24 on amazon. I'm sure you could find larger individual bits if needed.