Unused item. It was 3,400 yen on Amazon. K&F Concept NANO-K Series HMC VARIABLEND filter, 40.5mm size, offering high-quality optical performance. Variable ND filters are convenient lens filters that allow you to adjust a wide range of light reduction, such as ND2 to ND400 equivalent, with a single filter by rotating two polarizing films. - Model: NANO-K Series - Filter Type: HMC ND2-400 - Size: 40.5mm I accidentally purchased the wrong lens diameter. Thank you for looking.