you posted "i wanna know what guns they are for, what is the cup seal materials and why the different lengths
one has a clear cup seal and is bare metal
one has a black cup seal and is blackened metal stem and is slightly longer than normal cocker length
and the last has a black cup seal bare metal and is MUCH LONGER than a cocker
i know pics would help ill take pics tonight "
I answered the 1st question as to what guns based on the links provided.
The valve seats are a polyurethane or urethane base. The color doesnt mater much since it doesnt always match to hardness. One might be a little softer than the others. Soft seats seal better but I've found them to stick close. Stem finish is either going to be polished or blued. Again not much difference in performance as long as it is smooth.
What maker are you needing parts for a Sheridan or an AC?