The Lucroit Pro L Holder is specially designed for the following large-barrel wide-angle lenses, Canon EF 11-24mm f/4L USM, Mamiya Schneider Kreuznach 28mm LS f/4.5, phase one Schneider Kreuznach LS 28mm f/4.5 and the Carl Zeiss Distagon T 15mm f/2.8 ZE. The Lucroit holder uses donut adapters that fit over the lens to eliminate vignetting with these extreme wide angle lenses. The Pro L holder kit comes with French flags and barn door style visors for controlling reflections and lens flare.