My toilet rebate program is very specific in spelling out the tank and bowl product codes. Often in an ad the EcoDrake II, for example, will say that it's a CST744, which is the number of the bowl, but it won't specify the number for the tank, so I wonder if that is standard, or do I have to buy them separately?
The Drake and Eco Drake
ST743E, Watersense 1.28 gallon
ST743S, 1.60 gallon
The Drake II with double cyclone
ST454E, Watersense 1.28 gallon