What is the cfm on a GP201 fan?

All the GP series fans max CFM is at about 90. So after adding pipe and unknown resistance from below the floor the CFM will be some what less than 90.

our levels were 4-8 and just installed the GP501. How long would you think it normally takes the levels to go down - 1 day - 1 week? thanks.

I installed the GP501. It was easy. After 24 hours my radon levels dropped from 2.45 to .43. It could have just been an unusual day as my radon levels fluctuate. The true test is when the 7 day, and long term averages drop which I expect they will.

is this product listed by UL ?

Yes, the GP501 conforms to UL Standard 507 as tested by Intertek “ETL” testing laboratories.

Is this a complete package? do i need to buy any other parts to install? it's a new home and the builder i have a 3" venting pipe and an outlet.

You will only need a few parts. After you cut the 3" radon pipe in your attic, you will need two 3" Fernco rubber couplings or "girdles" (or at least that what we call them) and 4 appropriately-sized worm clamps to secure the radon fan's housing to both ends of the cut radon pipe. And of course, a flat head screwdriver to tighten the worm clamps. And I seem to remember that you will need a 120 volt pigtail wire/cord with a plug on it, as this was not included with the fan. And a few wire nuts and some electrical tape. Good luck!