I used flexible foil type I think it was slightly insulated made to use with this type of setup can be as simple as that. Came in a box say 25' long and you cut to size but you may need some tool to chop the spring steel coil. I used wire cutters fairly heavy duty ones. Might come with the clamps, need at least 3 clamps. For the exit hole I got a sheet metal tapered duct adapter at Lowes to exit the wall