This is a rare A42 Zeiss Ikon polarizer with the original leather case. Trace of cememt deterioration on the edge. A usual issue found on most vintage polarizer. As it is a push-on filter, you can easily use it on you Sonnar and Biogon.
Also with the set is a relatively rare Al frame 40.5mm Green (GR) and Orange (R) filter. Usually found is chrome on brass. Both in very nice condition, negligible sign of usage.