Heliopan 46mm Variable Gray ND Filter - 0.3 to 1.8 (1 to 6 stops) 704690
Amazon.com : Heliopan 77mm Variable Gray Neutral Density Filter (707790) with specialty Schott glass in floating brass ring : Camera Lens Neutral Density Filters : Electronics
Variable ND test: Heliopan vs Tiffen vs LCW mk II | CineD