how to position Camshaft sensor??

aiite if you dont know anything about it please dont act like you do.. k thanks.. i have a '97 Tsi.. I am currently in the process of rebuilding the engine.. and as i was cleaning the head.. i removed the Camshaft position sensor.. and the thing that bolts into the end of the Cam rotates around and the magnetic sensor reads where its at.. but the thing can go in the two ways.. anyone know how i can figure out which way the metal thing should be..?? bad terminology hahs "metal thing" if you know anything about it.. please let me know.. thank a bunch!!