Amazon.com : MAPIR Camera Lens 8.25mm f/3.0 16MP 41 Degree Narrow Visible Light RGB No Distortion HFOV S-Mount/M12 No Fisheye just fit with GoPro Hero7 Hero6 Hero5 : Electronics
Amazon.com : Entaniya ENT220 Fisheye Lens 220 Degree for Ribcage Modified GoPro Camera : Electronics
GoPro
Widen your view with the Lensbaby fisheye adapter for GoPro camreas - Bikerumor