Amazon.com: Freewell ND Filter Kit Includes ND4, ND8, ND16 and ND32 Filter (4-Pack) Compatible with Hero7 Black, Hero5 & Hero6 Black Camera : Electronics
Amazon.com : LENSKINS ND8 Filter for GoPro Hero 7 Black/Hero 6 Black/Hero 5 Black, Japanese AGC Optical Glass, 18-Layer Multi-Resistant Coated, Push-on Mounted, Weather-Sealed with Lens Cloth : Electronics