Concept Filter Frame Compatible with 4 x square filters Only for Concept matte boxes K&F 5.65'' K&F

The filter frame is exclusive to K&F Concept matte boxes and is not compatible with other brands of matte boxes. Filter frame is only for 4x5.65 inch square filters. After the lens is attached, it can be removed and reused. K&F Concept Filter Frame Compatible with 4 x 5.65'' square filters Only for K&F Concept matte boxes