reflective sheeting

hey im setting up a grow room and i need those big foam partitions that have the shiny stuff on one or both sides that iv seen before in different grow videos online. does anyone know where you buy those at?

This is the box after I got it in the attic . the inside dimentions are 49"x23"x33. I used a mixture of reflective roofing board. And styro board. Both seen to be doing very well. I have the box tied into the a.c. duct that was very close by (blocked off the vent below and redirected airflow...

Previous I had my grow space covered with those bubble car sun-shields from the dollar store, they actually work surprisingly well although I don't have numbers of their reflectivity. So in an attempt to upgrade I spent the last few days researching reflective sheeting and so I came across...