Amazon.com : K&F Concept 55mm 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
Review: K&F Concept 58mm Variable Neutral Density Filter - Infrared Conversions, IR Modifications & Photography Tutorials | Life Pixel IR
K&F CONCEPT 67mm 2-in-1 Variable Adjustable Filter Neutral Density Fader 5-Stop ND2-ND32 and CPL Circular Polarizing Filter Ultra-thin with Cleaning Cloth for Camera Lens - Walmart.com