installation size 4, airflow rate up to 265 m³/h2 performance classes, cut-out compatiblesecure contact with the housing wall via contact springsdegrees of protection IP 54 and IP 55, NEMA type 12UR and UL approvalUV resistance (IP 55 version, RAL 7035)cut-out compatible to installation size 4 of the 3rd and 4th Generation