Hoya Variable Neutral Density Filter - 72mm — Glazer's Camera Inc
Promaster 72MM Variable ND Filter
K&F 72mm Slim Neutral Density Fader Variable ND Filter Adjustable ND2 to ND400 | eBay
Amazon.com : K&F Concept 72mm 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