I have a sears Pak-A-Potti IV but it does not have a knob, it has a paddle type flush system. The paddle pulls straight out when you flush. My daughter thought it was the kind you step on and she busted the handle off. I drilled a hole in the stub and put a cord through the hole. It works.
The sears model is no longer made but you can get the flush bellows and seal at beta.searspartsdirect.com
Tom, August 2010
