Canon EF 11–24mm lens

The EF 11–24 mm lens is a professional wide-angle lens made by Canon Inc. It was announced on February 5, 2015, and at that time was the widest rectilinear lens ever made for the 35 mm format in either its film or digital versions.

The lens has an EF mount to work with the EOS line of cameras. Other than the front element, it is sealed against dust and water, and features a diaphragm which remains nearly circular. It produces minimally distorted images.

...
Wikipedia