Code3 had 3 different pulleys with 2 different sizes. The original size is 65MM and then they had a mid sized pulley. I do not know the size of that one (68 or 70MM I believe.). I think Doc has the mid size pulley and maybe can chime in. The mid sized pulley was somewhere between the original and stock sizes, and was designed to allow you to run a smaller than stock SC pulley in tandem with a larger crank pulley. The stock pulley is 74MM. Code3 did not make a 74MM pulley. If the pulley you received is 74MM then it is not a Code3.