PolarPro - GoPro HERO9/10/11 - Fifty-Fifty Dome - Marine-grade system - waterproof to 10-meters - 30% wider field of view - clean or replace without the use of tools: Amazon.co.uk: Electronics & Photo
PolarPro "Frame" Glass Neutral Density Filter for GoPro P1006
GoPro Hero 9 Black - POLAR PRO ND FILTERS - Cinematic Shutter Collection - Real World Footage! - YouTube