It seems Insul-Flue says you can pass a single wall stove pipe through their thimble. Am I reading this right?
http://www.woodstove-outlet.com/woodstove/Ocp34000.htm
http://www.dalsinmfg.com/insulflue.html
http://www.woodstove-outlet.com/woodstove/Ocp34000.htm
http://www.dalsinmfg.com/insulflue.html
"This unique system can be used with both single wall and double wall connector pipe."