GoPro Accessories: Neutral Density, Polarizer & Macro Filters for HERO4 Black & Silver
Glass Stick-on ND filter for GoPro Hero 5/6/7 – Camera Butter
Amazon.com : CamKix Diving Lens Filter Kit Compatible with GoPro Hero 5 and Hero 4 Session Camera - Enhances Colors for Various Underwater Video and Photography Conditions : Electronics
ETHIX TEMPERED ND FILTER FOR GOPRO 8/9/10/Session/Bones – NewBeeDrone
ETHIX Tempered ND32 for GoPro 8/9/Session
Amazon.com : Glass Stick-on, re-usable Neutral Density ND16 Filter for GoPro Session 4/5 V2 (ND16) : Electronics
Fotodiox GoTough Silicone Mount with Neutral Density 0.6 (ND4, 2-Stop) – Fotodiox, Inc. USA