TOTO USA, Inc.

Name	Model	Washlet S300 Elongated	Washlet S300 Round
Plymouth(E)	CST924	Yes	No
Dorian(E)	CST914	No	No
Pacifica(E)	CST904	Yes	No
Carolina(E)	CST884	Yes	No
Carlyle(E)	CST874	Yes	No
Supreme(E)	CST864	Yes	No
Supreme(R)	CST863	No	Yes
Ultimate(E)	CST854	Yes	No
Ultimate(R)	CST853	No	Yes
Ultramax(E)	CST854S	Yes	No
Ultramax(R)	CST853S	No	Yes
Baldwin(E)	CST784SF	Yes	No
Carrolton(E)	CST774S	Yes	No
Vespin(E)	CST764S	Yes	No
Dartmouth(E)	CST754SF	Yes	No
Drake(E)	CST744S	Yes	No
Drake(ADA)(E)	CST744SL	Yes	No
Drake(R)	CST743S	No	Yes
Promenade(E)	CST724	Yes	No
Carusoe(E)	CST716	Yes	No
Carusoe(R)	CST715	No	Yes
Reliance(E)	CST704	Yes	No
Reliance(R)	CST703	No	Yes

What if my Toilet isn't a TOTO Toilet? Will the Washlet still fit?
On a standard Toilet with no curves between the seat and tank, all you need is two inches of room past the mounting bolts. 

For more precise directions, follow the link below to the compatibility chart. Washlet S300 Compatibility Chart 


To ensure a proper Washlet fit on your current model, you can also use a box and ruler to check size and position. 
*Note: You will need to remove your current seat to check fit.