Fantastic little pancake lens. In beautiful condition, no scratches, haze or fungus. Comes with original front and rear caps.
Excerpt from the Canon Museum:
A super wide angle lens with a diagonal angle of view 82°, developed based on Topogon (manufactured by Carl Zeiss, Germany. Angle of view: 100°. f/6.3). This lens has a unique optical system: a spherical lens element with a very high refraction index is used as the first lens element and a special optical glass lens element with the infinite radius of curvature is used as the rearmost lens element. This lens was the fastest lens in the world as a 25mm lens at the time.