The differences between the EU version and a non-EU version of the Canon RF 200-800mm F6.3-9 IS USM lens are typically related to regional specifications, warranties, and compliance with local regulations rather than the lens's technical specifications.

### Key Differences:
- Warranty and Support: The EU version usually comes with a warranty and support that are specific to the European region, whereas the non-EU version might have a different warranty period or support structure tailored to the region it is sold in.
- Compliance and Regulations: The EU version must comply with EU regulations, such as those related to environmental and safety standards, which might differ from those in other regions.
- Packaging and Accessories: There might be differences in packaging, user manuals, and included accessories to accommodate local languages and regulations.
- Price and Availability: Pricing and availability can vary significantly between EU and non-EU versions due to regional market conditions, taxes, and distribution agreements.
- Return and Refund Policies: Return and refund policies can also differ based on regional consumer protection laws.

### Technical Specifications:
- The technical specifications of the lens, such as the focal length, aperture range, image stabilization, and compatibility with Canon EOS R cameras, remain the same regardless of the region.