K&F Concept 43MM ND8-ND2000 Adjustable ND Filter Camera Lense Variable Neutral Density With Multi-Resistant Coating for Camera Lenses(43mm) Camera Filters - Newegg.com
K&F Concept ND2 to ND400 Variable Fader ND Lens Filter for Camera DSLR – JG Superstore
Amazon.com : NEEWER 43mm MRC Variable ND Filter ND2-ND400, Neutral Density Adjustable ND Filter (0.3 to 2.7,1 to 9 Stops), Multi Layer Coated Optical Glass, Water Repellent & Scratch Resistant Ultra Slim
Amazon.com : K&F Concept 43mm Variable ND Filter ND2-ND32 Camera Lens Filter (1-5 Stops) No X Cross HD Neutral Density Filter with 28 Multi-Layer Coatings Waterproof (Nano-X Series) : Electronics