K&F Concept Variable ND Filter 43mm NDX, with a reduction range of ND2 to ND400, and a slim frame design, model KF-NDX43. I'm selling it because I sold my camera, so it's unused. I threw away the original case, so I'll include the case shown in the product photos. The product has been inspected, but please take a close look at the product photos to assess the condition. * Filter diameter: 43mm * Frame: Magnarium metal * Glass: Normal optical glass * Non-coating * Cross patterns may appear near maximum light reduction. Please note that this is a used item, so please be aware of this if you are concerned. I've heard about potential product swaps, so I'm sorry, but returns are not accepted. (I have checked the serial number.) The following is an excerpt from the product page: Variable ND filters are innovative items that allow you to adjust the amount of light reduction by rotating the front frame of the filter. The light intensity can be adjusted from ND2 to ND400, eliminating the need to change filters depending on the shooting situation. It allows for long exposure photography at any shutter speed while maintaining the resolution of the lens. Because it only reduces the amount of light without affecting color reproduction, it enables a variety of fantastic expressions, such as dynamic depictions of waterfalls and streams, light trails of cars at night, and eliminating crowds in the daytime streets. It uses high-quality optical glass with excellent color reproduction, and the frame is made of metal for secure attachment and excellent sealing, with a slim frame design that minimizes vignetting. It is a lightweight and durable filter.