When I was in grade school we went on a field trip to our local University's optics lab. In that lab was a sign that has stuck with me all these years. It said "Do not look into the laser with your remaining good eye". The joke is that you had *already* looked at the laser and lost vision in one of your eyes.

This solar filter reminds me of that. It is used for blocking the sun's rays so that you can take photos of solar eclipses and other phenomena. It darkens the image by 16.6 stops, with a filter factor of 5.0x. It is what NiSi call their "Pro Nano UV/IR Cut ND 100000".

It will help prevent damage to your camera, sensor, and lens during these solar events. HOWEVER: It is NOT rated for direct viewing of the sun, so please don't do that. It will not protect your eyes from direct viewing of the sun, so be sure to use live view and not the optical viewfinder.