Specifications:

Brand Canon
Focal Length 400mm
Maximum Aperture f/2.8
Minimum Aperture f/32
Lens Mount Canon RF
Format Compatibility Full-Frame
Angle of View 6°
Minimum Focus Distance 8.2′ / 2.5 m
Maximum Magnification 0.17x
Optical Design 17 Elements in 13 Groups
Diaphragm Blades 9
Focus Type Autofocus
Image Stabilization Yes
Tripod Collar Removable and Rotating
Filter Size 55 mm (Drop-In)
Dimensions (ø x L) 6.4 x 14.4″ / 163 x 367 mm
Weight 6.4 lb / 2.9 kg

Features:

400mm f/2.8 super-telephoto lens designed exclusively for EOS R-series cameras.

Optically identical to EF 400mm f/2.8L IS III USM lens.

Fast f/2.8 maximum aperture benefits working in low-light conditions and also affords significant control over depth of field for working with selective focus techniques.

Minimum Focusing Distance of 8.2′.

Includes three image stabilization operation modes.

Optical Image Stabilizer with up to 5.5 stops of shake correction.

Super Spectra Coating and Air Sphere Coating minimizes ghosting and flare when working in strong lighting conditions.

Compatible with Canon RF 1.4x and 2x extenders.

Customizable electronic focus ring with manual focus capability during SERVO AF.

9-blade circular aperture for beautiful bokeh at smaller lens apertures.

Two focus presets to instantly return to one or two memorized focus distances.

Dust and water-resistant design with fluorine coating on front element for easy cleaning.

Rotatable tripod collar for working atop a tripod or monopod.