Unfortunately I didn't take any pictures before it was finished. But I'll explain in more detail. First what you want is a heater with the spiral as you can see in the pictures. The nice thing is that they come with a seal, so just pick it apart from the water boiler. Then measure the hole in the water boiler and drill a hole with the same size in your bath. Then insert the seal and screw on the heater. Quite simple. I used the same kind of heater but a 2000W for my other bath. The PID is not the same it's an on/off kind. So I'd go for the Auber. I've search alot on the net and this is the best I could find that didn't cost alot of money. One other thing for the heater, it usually also come with a automatic overheating thing. I just removed all that stuff. All the electricity is wired to the PID and soldered to the heater (I'm not sure of my english here!) Hope this helps, I could maybe take some pictures of the inside if you like.