Solar filter observation card, 1"x4" filter window, 3"x5" card frame.
Suitable for naked eye observation of solar eclipses, large sunspots, Venus/Mercury transists without a telescope.
The sun will appear in a natural orange color when viewed through this filter.
Black polymer is the most common filtering material for observing the sun safely.
These viewers are a quality product of Thousand Oaks Optical, Arizona, USA. A manufacturer of safe solar filters for over 30 years.