Aluminum Polarizing Filter Circular Polarizer Filter Cpl Lens + Cap For Gopro Hero 5 Hero 6 Photography Accessories - Sports & Action Video Cameras Accessories - AliExpress
Amazon.com : CPL Polarizer Filter for GoPro Hero 11/10 / 9.with The Filter Adapter, You can Also use All 52mm Camera Lens Filters on Gopro 11/10/9 : Electronics
Telesin Polarizing Filter Circular Lens Protector Cpl Lens Filter For Gopro Hero 5 Hero 6 Hero 7 Black Camera Accessories - Camera Filters - AliExpress
FLIP11 One Filter Kit with DIVE Filter for GoPro HERO 5, 6, 7, 8, 9, 10, 11