This is a new brake lever. For use on the 1970 Yamaha DS6 / 250cc two stroke twin.

I believe that it is Genuine Yamaha, but am not 100% sure. What I am sure of it is made in Japan, and not Taiwan or china. Yamaha part number 233-83922-00-00. The ball head is 19mm across. The Taiwan copy levers are 18mm across the head of the ball.