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

[About clocks that synchronize time via radio waves] The function of clocks that synchronize time via radio waves only works in the Japanese area. Please be careful. 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