Lee Filters SW150 Mark II Lens Adapter for Canon Mark EF 11-24mm f/4L USM Lens (Holder Not included) Front Ring - Compressor Ring - Locking Ring - Lee Limited Lifetime Warranty (Note: All 3 Rings are supplied Screwed together, unscrew from each other before assembly. To fix the lens adaptor the lens must be off the camera Lee Filters SW150 Mark II Lens Adapter for Canon Mark EF 11-24mm f/4L USM Lens (Holder Not included)