Amazon.com : K&F Concept 77mm Variable ND Lens Filter ND8-ND128 (3-7 Stop) Waterproof VND Filter with 28 Multi-Coatings for Camera Lens (Nano-X Series) : Electronics
Amazon.com : Marumi 77 mm Digital High Grade ND16 Filter for Camera : Electronics
Amazon.com : NEEWER 77mm Magnetic Variable ND Filter ND2-ND32(1-5 Stops) with Magnetic Adapter Ring, HD Adjustable Neutral Density Filter with Water Repellent Double Sided 30 Layer Coatings, No X Cross : Electronics
Amazon.com : K&F Concept 77mm ND Fader Variable Neutral Density Adjustable ND Filter ND2 to ND400 Compatible with Canon 6D 5D Mark II 5D Mark III,Nikon D610 D700 D800 DSLR Cameras +
Amazon.com : K&F Concept 77mm 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