The piggy back tuner on my brothers car has a serial connection on the device and an open USB male connector on the other end, which just sits in the engine compartment. I tried it on an Apple USB end, but it's so slick it does not stay on as well. I also printed one for my Replicator USB cable which I always leave connected, if a file or xacto knife were to short the cable it would blow the Mightyboard.I printed this @ 10% and 1 shell (2 in total) - No support. My printer does .4mm walls so the clip portion is 2 walls thick. Make sure the portion above where the connector inserts is bridged properly as per the attached Repetier host image. Skeinforge likes to do the bridging direction based on X-Y.