There are two different schematics for this reel. The first one in this catalog 1983-84, and the second one 1985-88 with Cam. The only difference in the schematics is part #42 or 312240 called (Cam). I have a few of these reels, below are pictures of what I believe is the Cam. If I'm right then of all the 225's that I have none are of the earlier version. If the part I have pictured is the Cam and someone here has the earlier version of this reel without the Cam please post pictures that show the difference. Also if the pictures posted below are not the Cam please correct me. I have no idea what the Cam does other than what a Johnson catalog advertised (Patented CamDrive to boost retrieve power by 50% or more).