Super silent 12cm fan with s flow blades supplying 30 more airflow than a standard fan at the same speed the greater performance combined with pwm automatic speed control allows the fan noise to be kept to a minimum the apache fan creates more focused airflow providing blind spot cooling which makes it an ideal solution for a case or heatsink fan hdb hydro dynamic bearings extend fan life and further enhance noise reduction ip54 military standard ensures the fan is dust and moisture r