The OConnor Reduction Ring (114-95mm) enables using a lens with an outside front diameter of 95mm to fit into a Matte Box WM equipped with a bellows ring (not included). This arrangement prevents light from leaking from behind the matte box and flaring filters in front of your lens and is not suitable for use as a clamp-on ring. This reduction ring slides into your OConnor Matte Box WM outfitted with a C1243-117 Bellows Ring (not included) Prevents light from behind the camera leaking between your lens and matte box and degrading your image