Vocas 105mm to 95mm Step Down Ring for MB-3XX, Canon Wide Angle LensesVocas 105mm to 95mm Step Down Ring for MB 3XX, Canon Wide Angle Lenses When using a matte box as clip on, step down rings can be necessary, with or without thread. This ring is required when using a MB 3XX matte box as a clip on on a lens with a front lens diameter of 95 mm (for Canon wide angle lenses). Technical Specifications Manufacturer Vocas Systems Diameter 105 mm Mounting options Clamp Clip on Yes Material Industrial plastic Color Black Weight