Amazon.com : Hoya 52 mm Pro ND 200 Filter : Electronics
Amazon.com : Breakthrough Photography 52mm X4 6-Stop Fixed ND Filter for Camera Lenses Neutral Density Professional Photography Filter, MRC16, Schott B270 Glass, Nanotec, Ultra-Slim, Weather-Sealed : Electronics
Amazon.com : Heliopan 52mm Variable Gray Neutral Density Filter (705290) with Specialty Schott Glass in Floating Brass Ring : Camera Lens Neutral Density Filters : Electronics
Amazon.com : NEEWER 52mm 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