Panasonic's WhisperLine in-line ventilation fans are designed for easy installation and quiet operation (as little as 1.0 sones). With an efficacy rating of 3.3 to 4.2 cfm/w (cubic feet per minute per watt) of air they are very energy efficient. They have a long life condenser motors with thermal fuse protection rated for continuous use. The galvanized steel housings are insulated to reduce noise and condensation, and the duct adapters are tapered to facilitate duct connections. These in-line fans also feature an adjustable airflow control for multi-inlet balancing. Included are suspension brackets and truss or joist attachment brackets. The FV-10NLF1 model is pictured above. With these fans you can: Multiple task ventilation inlets in a single bathroom; i.e. shower, whirlpool, toilet, vanity. Ventilate two bathrooms with one in-line fan. Continuous (low rate) ventilation with multiple inlets throughout the home for indoor air quality improvement. You will need the adobe acrobat reader plug in in order to view the below spec sheets in PDF format. Voltage/Power (FV-10NLF1): 120VAC 60Hz, 0.31 amps, 36 watts Specs (FV-10NLF1): 120 cfm (0.2" static pressure), 1.0 Sones, 4" duct diameter Voltage/Power (FV-20NFL1): 120VAC 60Hz, 0.46 amps, 57 watts Specs (FV-20NLF1): 240 cfm (0.2" static pressure), 1.4 Sones, 6" duct diameter Voltage/Power (FV-30NLF1): 120VAC 60Hz, 0.86 amps, 98 watts Specs (FV-30NLF1): 340 cfm (0.2" static pressure), 1.7 Sones, 6" duct diameter Voltage/Power (FV-40NLF1): 120VAC 60Hz, 1.10 amps, 132 watts Specs (FV-40NLF1): 440 cfm (0.2" static pressure), 2.1 Sones, 8" duct diameter