Service Notice: EF 300mm f/2.8L IS II USM and EF 400mm f/2.8L IS II USM lens hood
Thank you for using Canon products.
It has been confirmed that, even when the lock screw for the lens hood on the Lenses is fastened, the lens hood may rotate when a certain amount of pressure is applied, but it will not detach from the lens. As a result, some specifications for the lens hood have been changed to address this phenomenon. For customers who may be inconvenienced by this phenomenon during shooting and would like to request a lens hood exchange, please contact the Canon Customer Support center in your region. The details are as follows.
Lens hoods for EF300mm f/2.8L IS II USM and EF400mm f/2.8L IS II USM interchangeable lenses for Digital SLR Cameras. Serial number: 770XXXXXXX through 841XXXXXXX
For customers who would like to request a lens hood, please contact your nearest Canon Customer Support center for a lens hood free of charge. This information is for residents of the United States and Puerto Rico only. If you do not reside in the USA or Puerto Rico, please contact the Canon Customer Support Center in your region. Please register your EF300mm f/2.8L IS II USM and register your EF400mm f/2.8L IS II USM. By registering, we will be able to notify you via email when future firmware updates become available for download. If you already registered, please ensure you are opted-in to receive the notification.
Customer Support Operations
Canon U.S.A., Inc.
Contact Information for Inquiries
Canon Customer Support Center
Support options and hours of operation: www.usa.canon.com/support