Pretty much any fill valve works on the Ultramax II
Korky with the blue or gray cap, the Fluidmaster with adjustable bowl refill, and the ones that come with, of which there have been several.
The one piece toilet will have CST604 marked inside the tank.
The box, if it comes with a seat, adds the numbering for whatever seat is in the box with it.
On this latest post, it's a T-connect bowl, which adds a hole for a concealed supply line for a Washlet. Some of those come with the SS124 seat that covers the hole if a Washlet isn't being used.
Korky with the blue or gray cap, the Fluidmaster with adjustable bowl refill, and the ones that come with, of which there have been several.
The one piece toilet will have CST604 marked inside the tank.
The box, if it comes with a seat, adds the numbering for whatever seat is in the box with it.
On this latest post, it's a T-connect bowl, which adds a hole for a concealed supply line for a Washlet. Some of those come with the SS124 seat that covers the hole if a Washlet isn't being used.