I purchased this new 2 months ago. I only used it to read codes. I did not download any tunes. Model # 989517-135. On the side of the box it says 2001 - 05 Big G. Duramax LB7 and LLY 135HP Tuner. Adjustable from 50HP to 135HP, 5 settings. List price $499. You can get them for $375. You an see pictures in my Garage. You can see the manual here: http://www.granatellimotorsports.com/pdf/manual60.pdf . PM me or email me. $275 mailed to your door.