The cable for the qc-35 comes with 2.5-inch that inserts into the Qc-35 and a 3.5-inch that inserts into the audio plug on a phone or computer. Such a cable should have come with your QC-35ii.
If you buy one, make sure it is one with 2.5 on one end and 3.5 on the other end. When you look at the two connectors side by side, you should see a difference. If they both look the same you have the wrong cable.