Heliopan 77mm Variable Gray ND Filter 707790 B&H Photo Video
Freewell 77mm Threaded Hard Stop Variable ND Filter All Day 2 to 5 Stop & 6 to 9 Stop - 2Pack
Bower 77mm Variable Neutral Density Filter FN77 B&H Photo Video
NiSi 77mm 1.5-5 Stops Enhanced Variable ND Filter
Amazon.com : NiSi 77mm Swift True Color ND-Vario | 1-5 Stops Variable Neutral Density Filter | Adjustable ND, True-to-Life Color, No Vignetting, Optical Glass with Nano Coating | Photography and Videography : Electronics