Genustech G-COAR Matte Box Adaptor Rings

A clamp-on adaptor ring is what holds a Genus matte box on the lens: it grips the barrel directly rather than threading into the filter ring, so the matte box sits square and the front element stays free. Genus publishes the ring in four barrel diameters, 80, 95, 110 and 114 mm, and the one you need is set by the lens, not by the matte box.

The 80 mm ring is the rod-mount version for the Genus PV, GWMC and GML Lite matte boxes. The 95, 110 and 114 mm rings are clamp-on rings for the Production matte boxes, GPMB and GPMB Kit. The G-COAR82P is the center coar for the Production matte box rather than a barrel clamp.