Screws for Canon EF 100-400 (f 4.5-5.6) mm IS lens II

[WGrebe1967]

For the silver lens mount of the lens in subject line I know screws are part number XA1-7200-806. Where can I purchase them?

Also what size JIS(crosscut) screwdriver should I use for these screws ?

[Mark35mmF2]

Hey there,

You can reach the Canon Parts Order Desk at (866) 481-2569. They are  available from 9:00 A.M. to 7:00 P.M. EST, Monday through Friday.

I do not know which size screwdriver to use, I'm sorry, but the parts desk may have that information.

[WGrebe1967]

I called parts desk but person who answered phone did not know what screwdriver size I should buy.