From the Manufacturer LensCoat for the Canon 400 f/5.6 Realtree Max4 HD. LensCoat telephoto lens covers offers your valuable equipment some protection from scrapes and bumps, preserving its resale value. It also help break up the shape of your lens, making it less noticeable to wildlife. The LensCoat 400 has small hole on the last segment lines up with the red dot indicator, making it easy to quickly line up your lens with camera mount even with the cover installed. Please note that the new version of this LensCoat covers the lens when the hood is extended.