Wonderpana 66 Essentials .6 SE Kit for Canon 17mm TS-E Super Wide Tilt/Shift f/4L Lens with 6.6 x 8.5" Graduated Neutral Density 0.6 (Grad-ND4, 2-Stop) Soft Edge Filter and Circular Polarizing Filter (CPL) Premium Grade Anodized Aluminum WonderPana 145 Core Unit with Wonderpana 66 6.6" filter bracket for the Canon 17mm TS-E Super Wide Tilt/Shift f/4L Lens Silm double threaded Circular Polarizer (CPL); made of high quality optical glass Optical polycarbonate (CR39) 6.6 x 8.5" Graduated Neutral Density 0.6 (Grad-ND4, 2-Stop) Soft Edge filter Fits Industry Standard 6.6" Wide Filters, up to 4mm Thick (such as Schneider Optics) and all 145mm x 1mm standard thread filters 24 Month Manufacturer Warranty