Yeah...I was thrown when he said you could just use the happ ones with the I-Pac. I knew that the Happ optical rotary sticks needed an Opti-Pac, not an I-Pac, so I figured maybe there was something I didn't know about the Happ Mechanical Rotary sticks (which would have kind of sucked since I've already purchased Happ mechanical rotary sticks and a druin interface -- haven't hooked any of it up yet, though).