Amazon.com : ProMaster 58mm Variable Neutral Density Filter : Camera Lens Neutral Density Filters : Electronics
Amazon.com : 58mm ND Variable Neutral Density Filter for Canon EF 28mm f/2.8 is USM Lens : Electronics
Amazon.com : K&F Concept 58mm 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
Amazon.com : Kenko 58mm PRO ND100 Multi-Coated Camera Lens Filters : Camera Lens Neutral Density Filters : Electronics