They are marked Keihin 42ADSC. I Apparently later models used fixed jets, but these are the screw in changeable ones. These carburetors were purchased from a long time Honda dealer that closed. Look at the pictures, aside from some "shelf wear" these are like new carburetors, CV slides move easily and when I removed all four carb bowls, they are so clean, I wonder if they have ever seen gasoline. I have been informed by Honda experts that these were used in both Honda CB750 and CB900 please be sure they are for your application and please feel free to ask any questions before purchasing.