You had to make me get out of my computer chair and walk out to the garage. Yes, you are right it is a 403. Latly my bigest problem has been that the motor won’t turn on. I have to rock the filter around and give it a good old fashion knock. Then it will start working. Since I have it in the garage now. I take the garden hose and force water into the intake tubing. I don’t keep it in the house any more because one night I awoke to the sound of water poring on the floor of my bedroom. Some how the out take tubing worked itself loose and fell off the back of my tank. At four in the morning it is not fun to mop up nearly thirty gallons of water. Luckily I have tile flooring in my room, otherwise I would have been in big trouble. Jonathan Scute Mod