Duct Work Fan Booster?

Hey guys. New here. I'm creating my small grow cabinet, and just installed a 4" inline duct fan booster as an exhaust to a homemade carbon filter. I'm hoping for a passive intake. It seems to pull a lot of air. But the cabinet isnt done yet and havnt tested. It measures (LXWXH) 24"x12"X28". Ill be runnign CFLs. Just wondering if anyone has used these "fan boosters" and if their efficient/worth $25.
Thanks, Pics soon! (when i transfer to new cabinet(1st grow)) - Think i can do 2 ladies?

I tried one with a 400 watter. Didn't work out to well. I couldn't put a carbon filter on it cause the cfm just dropped right out. Even with out the filter the temps was still way to high. So my experience it was worthless, but my cabnet was 30"x30"x48". It's bigger then yours. It might work for you. One way to find out. Give it a try.

I'm going to try a 6" Booster dust fan/filter in a closet. I figure if the flow is cut too much by the filter I can easily add a second booster. Though Trial and error may change my mind...