K&F Concept 58mm Variable ND Filter ND2-ND400 (1-9 Stops) with Putter HD 28 Multi-Layer Coatings Import AGC Glass Adjustable Neutral Density Filter for Camera Lens Camera Filters - Newegg.com
Amazon.com : K&F Concept 58mm Variable ND2-ND400 ND Lens Filter (1-9 Stops) for Camera Lens, Adjustable Neutral Density Filter with Microfiber Cleaning Cloth (B-Series) : Electronics
Gear Review: 4 New K&F Concept Filters Put to the Test
Review: K&F Concept 58mm Variable Neutral Density Filter - Infrared Conversions, IR Modifications & Photography Tutorials | Life Pixel IR
Testing the K&F Concept ND1000 neutral density filter
Amazon.com : K&F Concept 37mm 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
Variable ND Lens Filter Cap TPU 67-82mm - KENTFAITH
95mm ND1000 (10 Stop) Fixed ND Filter Neutral Density Lens Filter for DSLR Camera - KENTFAITH