This is an early autofocus 300mm lens. Be aware that it uses the old AF system and requires a camera body with a motor built in (ask if you are not sure). The autofocus is not as fast as the newer versions but the optical quality is similar and the lens is a lot more affordable. If your application does not require fast AF then this lens is a winner.
This lens is dead mint and looks unused. It comes in the CT-303 case with the original shade and caps. You will not find a cleaner example.