I didn't find anything about them here so I thought I might share these ones: They are called SBH7 and were made as ABC protection gloves for the army (NVA) of former GDR. They are made from a heavy and thick rubber but still are very soft and flexible. What I like: They have texture for better grip, which is not so usual on heavy rubber gloves. They have elbow-length (about 40 centimeters). I really love them. As you can see, this pair was manufactured looong time ago in 1978.
Greetings!