This is the very late model of the 135/4 Sonnar for Contax RF. For such late more, no more Red T mark. Barrel is like this for most 85 and 135 Sonnar with Alumimium barrel. Clean and clear, no oil on blades. Comes with home-made rear cap and cheap front cap.
This lens is ideal for use on Sony A7. Recently tested on A7R with excellent result. In case you have the adapter already, it is a very good choice.