40.5x0.5mm Filter - OC-12 for Jupiter-11 lens
This filter was purposed originally for 135mm lens of turret Konvas. But it can be used on other lenses that have 40.5x0.5mm filter thread.
Used condition, needs some cleaning.
Orange filters are used to highlight clouds and white buildings against clear sky, to eliminate haze, and to increase a picture contrast. Recommended for B/W film.