I got 2 that push 72 cfm . 1 pushing hot air up top , 1 pulling cool air at bottom of a 36 cubic ft. 250 watt hps c-13 cabinet -n- mine work great . But I do have a cheap ass 20.00 4in. duct booster fan drawing heat off the hood n out of cabinet also .
Peace
Crispi :jointsmile: