If the cross section of the fat section of that one is circular with a 'square' lug sticking out which runs the length of the fat section, then that's one of the ones which fit into a slot on the inside of the shifter, so over the end of the outer cable at the shifter end (on 105 and above anyway). If it's just circular then it's either the chainstay one or one of the downtube ones. The chainstay ones have a longer 'tail' (maybe).