So got this, did the install and works like a charm. Quiet and the thermostat works too. Other people complained about noise and vibrations, but I guess because it was not installed properly. Keep in mind the box contains only 4 screws to attach the brackets to the shroud, you'll need some additional stuff. So this is what I did:
1. Got a 3/4 plywood scrap from a hardware store, 8 rubber grommets, 8 lag screws, 8 washers, 1 tube silicone.
2. I've cut a round hole 15-1/4" in diameter (1/4" larger then the manufacturer suggests in order to apply the silicone to absorb vibrations).
3. Attached the brackets to the shroud with provided screws.
4. Attached the fan to the plywood: plywood - washer- rubber grommet-washer -lag screw. Do not overtight the lag screws(check the pictures).
6. Applied silicone between the plywood and fan (reduces vibrations also increases efficiency).
7. Ran the power cable through a switch inside the house so I can control when to shut it down in case I need to.
Total additional cost ~$15.
I'm giving it 4 stars because of the trip I had to take to the hardware store to buy all these. Wish the manufacture will include the screws for the plywood and the rubber grommets.

Works nicely and it is really quiet.
Highly recommended!

I'm utilizing this fan in a do-it-yourself whole house fan project mimicking the QuietCool setup. It's working very well controlled by a wall switch (thermostat removed) with butterfly damper intake mounted in the attic access cover in bedroom closet. The fan is mounted to joists in the attic connected to the intake air supply by 10 feet of 16" ducting. The economical cost of the fan along with the high CFM rating make this an ideal choice for my project instead of using multiple dual window fans. The house is a 2100 sq ft two story.

This ventilator/fan is poorly constructed and engineered. Before installation, I bench tested the unit and the fan blade was hitting two of the bolt heads that secure the fan housing mounting brackets. I the had to drill 4 new holes in the fan housing to move the bolts away from hitting the fan blade.

The fan housing and the fan motor mounting hardware, is constructed using very "thin" gauge steel. After installation, the fan has a noticeable wobble. I attribute this to the "thin" gauge steel not being rigid enough to handle the torque of the spinning fan.

It read on the box "Made in USA". I thought I would be getting American engineering and quality workmanship. Not to be found!!

It appears that the engineer who designed this unit, specified a thinner gauge steel to save on construction costs. In this day and age, this does not surprise me for something made in China. BUT "NOT" IN THE USA!!!

So now I have a wobbly attic fan in my garage. It's securely mounted, so the vibration isn't all that audible yet.
I don't expect this fan to last very long. I'll report back when this thing self destructs......

PS..I was asked the horsepower of the motor. It wasn't marked. If you do the math, 2.1A x 120V = 252W. 1HP = 746W. Then 252W divided by 746W = .3378 HP. (that rounds off to 1/3 HP)

Northern Utah installation.

Pros:
Higher efficiency motor than many available and than the one I'm replacing.
Made in USA.
Lifetime warranty.

Cons:
All motors for this purpose have un-sealed, non-permanent, non-serviceable bearings.
Non-serviceable bearing will go out in about 13 years or less.
Unbalanced fan. It wobbled/shook badly so I balance it to make it and the installation last longer with less noise and more efficient electrical usage.

I purchased this motor/fan unit for a customer to replace a motor with bad bearings. The original was manufactured by L.L. Building Products in January 2000 and it went bad July 2013. I am not sure how many hours this old motor has on it. It was set to 100F degrees (attic temperature) so my initial guess is maybe 1000 hrs a year = 13,000+ hrs. I wonder what mfr rating on is? After research and asking other people who use these, 13 years seems to be the upper average lifespan.

A motor by itself costs the same as this whole unit and has a warranty of only 1-2yrs. I paid $79 July 2013. This whole unit comes with a housing and a thermostat and has a lifetime warranty. This motor is higher efficiency which means the same output while using less electricity than the others that use 4.3 amps, like the one I am replacing.

I opened the box and inspected the unit. The housing was bent out-of-round, partly from shipping but, mostly from sloppy manufacturing of the motor brackets and sloppy assembly of them. The brackets are made smaller than the motor diameter enough that they bend too much when assembled/tightened. If not tightened exactly the same amounts little by little they pull the motor off-center. I hooked it up to power and the fan scraped the housing and wobbled/vibrated. The shaft appeared to be straight so I determined the fan was not balanced.

I needed to get this installed for my customer sooner than later to provide great service and keep them happy so I spent about an hour getting this thing in a good enough condition which I would be willing to install it for any of my customers. I tweaked the brackets and realigned the motor, then pain-stakenly balanced the fan so there is nearly no wobble.

I hope this lasts long enough to satisfy the customer or I may have to eat the labor cost of replacement under the lifetime warranty.

What happened to quality of USA products? I wonder if it is truly made in USA or if it is merely assembled in USA. Basically everyone would rather pay Chinese prices, and companies are giving lower quality to keep prices low and stay in business. Manufacturing companies/employees are mostly sell-outs, lacking integrity to do what is right. The original companies which started the shift to China are mostly to blame, but then it was the same thing with Japan and after China there will be another cheap labor nation.

I installed two of these in a 1600SQF attic (overkill but whatever) on a wall switch that I can control if I want them off for any reason. They do exactly what they were supposed to do and the best price on the internet.
I left them on the thermostat and they come on and go off as the temps go down in the attic

*****UPDATE***** These fans are awesome! As I mentioned above, I installed two. I put one in a gable vent and the other in the attic area blowing into the garage......it works awesome. The reasoning I had was the upper thermal layer would be taken care of by the upper fan and when the lower thermal layer exceeded 90* then it would be taken care of by the lower fan. They are both on a single pole switch so i have the option to cut power to them if I wish. In my opinion it is imperative to build a shroud/frame for these. It operates on the same concept as an automotive fan in a shroud.

Granted, my SoCal days haven't risen above 90* so far this year. Prior to installing these fans, my a/c would have been on by noon and stopped cycling around 8 pm trying to compensate for the attic heat soak. As it stands, the house remains at 75* max (in the vaulted ceiling area....the bedrooms are 70*). I AM VERY HAPPY WITH THE FANS!!!!!