The Canon EF 400mm f/2.8L IS II USM is a lens that's designed for the great outdoors and, as such, has particularly sturdy build quality along with weather seals to guard against dust and moisture.
There's also a rubber O-ring fitted in the metal mounting plate to form an environmentally sealed fixing between lens and camera.
Construction of the barrel is based on magnesium alloy and titanium components and, heavy as this ultra high-performance super-telephoto lens is, it's still 1.5kg (28%) lighter than the first edition.
This makes handheld shooting quite feasible, at least for short periods of time. For extended periods of shooting, a monopod makes the lens much easier to use.
Handling of the Canon EF 400mm f/2.8L IS II USM lens is very refined with smoothly operating, high-precision controls in every area.