we got it at homedepot heres the link
Inductor 4 In. In-line Duct Fan - DB204 at The Home Depot
i cant find that flexible exhaust piping on the website that you see in the pics but thats where we got it. all we used to cut the holes was an exacto knife.
and yea for the intake its just a hole, and it works because that exhaust fan pulls the air out of the box making a suction affect. you gettin me?
get back, w o w