where to get an exhaust coupler

[sxi4evr]

where can i get a 4 inch id silicone exhaust coupler for my factory pipe?

thanks

 

[Mark44]

McMaster Carr.

Mark44

 

[sxi4evr]

http://www.mcmaster.com/#silicone-coolant-hose/=78skhu
this it? is there anywhere cheaper?