Steel angle pin installation. Angle pins are used where there is pull on the line to one side, such as where the line changes direction. The lineman took a regular pin and installed it in a hole drilled at the appropriate angle, making it an angle pin installation. This is one example where removing the pin from the crossarm it would lose all it's history. I believe this pin to be an earlier style as it has no shoulders and is shorter than most that I have seen.