110 box and will work on all 6.0's 03 to current. i love this box and have had this box for 12months and it is and still is great box for the person who wants to add 110hp w/o damging there investment. the truck runs like a rapped ap. i don't 1/4 mile with it but overall performance is unreal. it raised my mpg a whole 2 miles to gallon and firmed up my shifts. it is adjustable w/ reostat. the down side is tends to make the rear tires bald in the middle. :Thumbup: i am upgrading to a box which reconfigures the shift patterns an lock up's if the ts box was able to do this i would still own this box. no bs i really like this box and i may be making a mistake. my loss your gain 500. for the person looking for a good middle of the line box which wouldn't make your truck puke and destroy the trans this is the one.