I have the older style 4-way, 2" in & 1-1/2" outs with the driveshaft. It' on a 120 with an ampmaster 3000. I set it up end of august 2005 and so far, I haven't had any problems. I bought version 1-2-3 drums. I am currently running the version 2 drum. Mounting the unit above the tank water line makes switching drums much easier. My only complaint is that the port switching speed is fixed. The ports switch every 15 seconds. I would rather see them switch every 5 minutes or so.