What is the best friction call for making fighting purr?

[DMTJAGER]

I am quite intrigued by the fighting purr Toms make and think it would be a great call to try on a Tom hanging up just out of range. 

Not having a lot of luck making it on my synthetic glass pot call and would like to know what pot call surface type is best for making it be it natural slate, copper or aluminum or a synthetic glass pot call I do not own.
Or is there a push button call I am unaware of that is my best choice.

Thanks
Art.

[Gooserbat]

I like Aluminum pot calls.  I know a guy who makes I good one ?

[quavers59]

Without a dought-- a Double Slate will make awesome Fighting Purrs. Agrressive Purrs near the Rim and in the Middle to imitate 2 Pissed Off Gobblers going at it.

[bbcoach]

Slate for me as well.  I've had great success with a split v diaphragm when I purr aggressively out of each side of my mouth also.

[Tom007]

Don't forget 2 good push buttons. Shannon does a great fighting purr..........