The noise level of PWR-01 series is as follows:

Fan rotation speed: Max. speed
Reference standard: JIS Z8731
PWR401L: 54 db
PWR801L: 55 db
PWR1201L: 60 db
PWR2001L: 65 db

Please note that the airflow rate of PWR-01 series varies depending on the internal temperature rise.
When the hyper breeder is turned on, the fan rotation speed is always at maximum speed.