standard fans ( 37,7dB 2500rpm airflow 70,6cfm )
the nf f12 pwm ( 22,4 dB 1500rpm airflow 93,4cfm )
the industrial versions ( ca 29,7dB with 2000rpm airflow 121,8cfm )
i got the nf f12pwms and use 1 of the low noise adapters to run em with 1200 rpm, diiference from "corsair vacuum cleaner" to the noctua silence is great
ek vardar is also a great and silent brand or bequiet silent wings,