I am having two new Kohler Serif two-piece toilets put in new construction by my plumber in a few weeks. He only uses the typical wax ring so I am somewhat reticent to suggest the wax-free seal before researching it a bit, or getting TL's advice. What is your opinion of this one Terry?
http://www.fernco.com/FTS.html
http://www.fernco.com/FTS.html