Before buying the Freewell Insta360 Luna Ultra ND Filter, confirm that your camera or drone model is Luna Ultra. Freewell filters are made for specific camera housings, so a similar-looking DJI or Insta360 model may still need a different filter size or mount.
Next, check the job you want the filter to do. This product is best for long-exposure work, such as smoothing water, clouds, or daylight motion. If your goal is only basic lens protection, choose UV protection. If you need shutter-speed control in bright sun, choose an ND or VND option. If reflections are the problem, look for PL, CPL, or ND/PL in the product name.