Vocas 105mm to M37 Threaded Step Down Ring for MB-2XXVocas 105mm to M37 Threaded Step Down Ring for MB 2XX 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 2XX matte box (with 105 mm front diameter) as a clip on on a lens with internal M37 thread. Technical Specifications Manufacturer Vocas Systems Diameter 105 mm Mounting options Screw in Clip on Yes Material Aluminum Color Black Weight (gr.) 58 EAN 8720041002147