where can i find the model # on my toto toilet?

I told my builder to order and install 5 MS854114S toto ultramax in my new house. I've checked under the lid and i don't see the GMAX, i see POWER GRAVITY.

I can't find the model number in the tank anywhere, it has these numbers but none of them look like model numbers. IS it hidden somewhere?

One quick way to tell is:

The G-Max uses the Red flappers

The Power Gravity uses the Blue flappers.

One piece Toto's will have the model # stamped in black inside the tank on the back. It should say CST854S for your toilet.