46mm Nd2-400 Neutral Density Fader Variable Nd Filter Adjustable For Panasonic Lumix G2 G3 G6 G7 Gf2 Gf3 Gf6 Gx7 14-42mm Lens - Camera Filters - AliExpress
46mm ND2 to ND400 HD Slim Fader Variable Neutral Density ND Filter K&F Concept | eBay
Amazon.com : K&F Concept 46mm Variable ND Filter ND2-ND32 Camera Lens Filter (1-5 Stops) No X Cross HD Neutral Density Filter with 28 Multi-Layer Coatings Waterproof : Electronics
Amazon.com : 46mm Variable Neutral Density Filter for Panasonic Lumix G 20mm F/1.7 Lens : Electronics