Panasonic ventilation fans are engineered for 100,000 hours of continuous use!  They are very quiet - Panasonic ventilation fans have a defect rate of less than 0.0006%! Many of the different models are energy star rated.  The warranty on these units are 3 years.

Here we present Panasonic WhisperFit - Low Profile Exhaust Fans With High Profile Performance From 50 - 110 CFM.

Panasonic the name itself signifies digital performance to the to the level of perfection. These fans from Panasonic VF2 WhisperFit ventilation fans are not only as energy efficient as conventional Panasonic Ceiling fans, but also they are as compatible with either 3 or 4 inch duct and are only 5.5 inches deep. They are rated for their quiet performance and continuous operation including a built-in backdraft damper, thermal fuse protection, and rust-proof paint on the galvanized steel body. The grill trim is white. Voltage and power requirement is 120VAC 60Hz, 0.12 to 0.18 amps and it has the approval  of  UL also it is listed for use in a tub and shower with GFCI branch circuit wiring.