Fotga 52mm Slim Fader Variable ND Filter Adjustable Neutral Density ND2 to ND400|Camera Filters| - AliExpress
Round Continuously Variable Metallic Neutral Density Filters
Amazon.com : K&F Concept 72mm Variable ND2-ND400 ND Lens Filter (1-9 Stops) for Camera Lens, Adjustable Neutral Density Filter with Microfiber Cleaning Cloth (B-Series) : Electronics
Bower 55mm Variable Neutral Density Filter FN55 B&H Photo Video
Amazon.com : JJC 82mm Variable Neutral Density Filter ND2 to ND400, Slim Fader ND Filter for Canon EF 24-70mm f/2.8, EF 16-35mm f/2.8, Sony FE 16-35mm f/2.8, Nikon 24-70mm f/2.8 & More
K&F Concept 43mm Fader Variable Neutral Density Filter Adjustable ND2 to ND400 | eBay
Tiffen 82mm Variable Neutral Density Filter : Target