It is a SXT-125. My dad bought two of them brand new for us to ride together. One was red, the other, blue. They were AMF Harleys. The chain had two masterlinks. If you took out the piece of chain between them, you could use the smaller sprocket..I think it had 38 teeth. With the small piece of chain in there, you used the larger sprocket (71 teeth). That thing could climb trees!