little air restriction?!?!?!??!?!?! i got the aluminum ones which hurt airflow less than the plastic ones, but i noticed a 30-50% decrease in airflow........they are USELESS.....your case doesnt get THAT much dust in it anyway......ive had mine runnin for 3 months now, and when i open it up i can barely see some dust particles.......its just a waste of money, and i found out the hard way........