82mm Slim Fader Variable ND Filter Adjustable Neutral Density ND2 to ND400 Filter for Canon Nikon Camera Lens ND Filter|nd2 to nd400|filter for canonneutral density - AliExpress
Genus 77mm Polarizer ND Variable Filter : Electronics - Amazon.com
Tiffen 77mm Variable Neutral Density (ND) Filter - 2 to 8 Stop 77VND