It was made in the first part of 1955. They were just called R50's. They put a larger tail light and some other things on it and called it a /2 later that year. I have the larger tail light because my friends highway peg took out my original one, and I have been unable to find one since. Essentially, the same bike, but R50s are more rare. Also, the tiny tail light is dangerous, and I ride mine. I could call it a /2, but it is not.