A flash differ that slides over the flash head. Diffuses the hard light into a softer light. useful for product photography. Should also work for the EXII for the Canon version.
PRINT IN TRANSPARENT PLASTIC
It is important to use a clear/transparent plastic because white PLA creates a very yellowish hue. In contrast print in other colours to create an artistic colour similar to using filters. Experiment!
Re-orient the part so that the flat side is on the bed if it isn't already.