Amazon.com : Step Up Lens Filter Adapter Rings - Set of 9 - Allows You to Fit Larger Size Lens Filters on a Lens with a Smaller Diameter - Sizes: 37-49, 49-52, 52-55, 55-58, 58-62, 62-67, 67-72, 72-77, 77-82 mm : Electronics
Meike Drop-In Filter Mount Adapter EF to EOS-R MK-EFTR-C B&H
BEST ND FILTER ADAPTER FOR THE SONY RX100 VII: MAGFILTER VS LENSMATE - YouTube
NEEWER Magnetic Variable ND Filter with Adapter Ring - NEEWER – neewer.com
Kipon launches EF to Sony E adapters with built-in variable ND filter: Digital Photography Review
Amazon.com : Meike MK-EFTE-C VND Drop-in Filter Auto-Focus Mount Lens Adapter for Canon EF/EF-S Lenses to Sony E Mount Cameras with Variable ND Filter and UV Filter A7SII A7 A6000 A6500 A7SIII
MEIKE MK-EFTR-C EF-RF Drop-in Filter Mount Adapter for Canon EF to EOSR with Variable ND Filter and UV Filter
KIPON Mark 3 Neutral Density Autofocus Lens EF-S/E AF ND MARK 3