Designed For Easy Installation. The LEE SW150 Mark II w/ Canon 11-24mm f/4L Lens Adapter Kit consists of the SW150 Mark II Filter System Holder for Wide-Angle Lenses and the SW150 Mark II Lens Adapter for Canon EF 11-24mm f/4L. The lens adapter consists of three components: a front ring, a compression ring, and a locking ring. Placement of the lens adapter onto the lens is easily accomplished by sliding the front ring over the built-in hood with the front ring’s integrated lugs positioned away from the lens body. The compression ring can then be slid over the rear of the lens until it meets the front ring. Finally, the locking ring is also slid over the rear of the lens until it can be screwed into the front ring. After that is accomplished, an SW150 Mark II Holder can be placed over the adapter from the front of the lens for use.

Filter Use & Durability. The lens adapter is curated from a durable aluminum-alloy construction, and extra protected by the plastic SW150 Mark II Filter System Holder. You are able to stack 2 filters at a time in the filter holder, avoiding vignetting by setting the lens to a focal length no less than 13.5mm. When using one filter, vignetting can be avoided by setting the lens to a focal length no less than 12.5mm