The name Summaron is used by Leica to designate camera lenses that have a maximum aperture of f/2.8 or f/3.5 or f/5.6.
It was manufactured until the 1960s and over 100,000 units were produced, making it one of the most common Leica wide-angle lenses ever made.
[2] Several lens has been designated with the name Summaron, confusingly with a variety of f-numbers.
The only thing in common between these lenses were that they were generally wide-angle and extremely small (sometimes referred to as pancake lenses).
The Summaron are some of the smallest lens in the Leica range, but because of its low maximum aperture it is cheaper than other lenses.