Amazon.com : K&F Concept 40.5mm 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
K&F Concept 40.5mm Lens Filter Kit ND1000 Neutral Density and CPL Circular Polarizing Filters - KENTFAITH
40.5mm ND2-400 (9 Stops) Variable ND Filter Neutral Density Filter for Camera Lens - KENTFAITH
Amazon.com : K&F Concept 40.5mm 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 : Pixel ND400 40.5mm ND Lens Filter (1-7 Stops) Adjustable Neutral Density Filter for Camera Lens : Electronics
40.5mm ND Filter ND2-400 Neutral Density Fader Variable for Sony E 16-50mm lens | eBay
Graduated Neutral Density 0.9 Gnd Nd Filter 3-stop For Canon Nikon Sony Fujifilm Lens 37 43 46 40.5mm 49mm 52mm 55mm 58mm 62mm 67mm 72mm - Camera Filters - AliExpress