Master Flow 20 in. Aluminum Gable Mount Automatic Shutter-SGM20 - The Home Depot

Master Flow

Model # SGM20

Internet # 100092056

Store SKU # 372522

20 in. Aluminum Gable Mount Automatic Shutter

Master Flow 20 in. Aluminum Gable Mount Automatic Shutter

This item has been discontinued.
The Home Depot no longer carries this specific product.

$44.45 / each
  • Gable Mount Automatic Shutter
  • Use with Master Flow models PG2 and PG3
  • Aluminum construction


Model # SGM20

Internet # 100092056

Store SKU # 372522

Store SO SKU # 813317

Automatic 20 in. Power Gable Vent Shutter. Power Gable Wall Louver designed to be used with MasterFlow PG2 and PG3 Gable Power Fans.

  • Use with all attic power gable mount vents
  • Moving air opens the louvers only when the power vent is operating
  • When vent is off, shutter helps prevent infiltration of rain, snow, insects, etc
  • Maintenance-free white aluminum construction (can be painted)


Assembled Depth (in.)  1.5 in  Assembled Height (in.)  19.25 in 
Assembled Width (in.)  19.25 in  Cut-Out Diameter (in.)  16.5 
Product Depth (in.)  1.5  Product Height (in.)  19.25 
Product Width (in.)  19.25 
Base Included  No  Color Family  White 
Color/Finish Family  White  Material  Aluminum 
Power Type  Turbine  Product Weight (lb.)  4 lb 
Reccommended Sq. Ft.  Returnable  90-Day 
Ventilation Type  Other  Wildlife Guard  No 
Warranty / Certifications
Manufacturer Warranty  4-year Limited Warranty 


Rated 3.4 out of 5 by 12 reviewers.
Rated 4.0 out of 5.0 by Great product...some concern This is a great shutter for the money and it was easy to install; just use the template provided. If you're using a saws-all instead of a jigsaw you may want to add 1/4" to the all four sides. Once installed, the shutter performed flawlessly. I had to build the 20 x 20 inside frame laying flat instead of laying on edge, (as pictured in instructions), because I was installing on T1-11. But the frame, (either way), is a necessary step in order to have a solid back to screw louver on to; plus it helps to keep out roaches. Regarding the shutter and its design to open and self-close upon the outflow air from the fan, I'm concerned that a sudden updraft from a rain storm could cause it to open (I live in central Florida) but this is only a concern at this point and it has not happened. In the event of an approaching hurricane, I would suggest purchasing or having a custom built waterproof and wind resistant enclosure (on hand) to cover the shutter completely. August 27, 2014
Rated 4.0 out of 5.0 by 20" Power Gable Vent Shutter This product is a fair product for the price. However, be aware that the rough opening for this product is 16.5" X 16.5" and not the 15.25" x 15.25 " stated in the product specifications that are listed on line. Also be aware that if there is any natural draft through this product that the louvers will open. This happens as they are not very heavy and only close by thier own weight and gravity. Any time there is a slight positve pressure on the back side of these louvers they will open. May 27, 2009
Rated 5.0 out of 5.0 by Excellent Works Perfectly Looks Great! I actually had someone install this for me because I am disabled but it works perfectly and looks fantastic and I believe is well made. August 21, 2013
Rated 4.0 out of 5.0 by High quality, well-made item When my house was built, for whatever reason, the builders failed to include attic ventilation. I finally got around to doing it this year, and decided to go with this (the SGM 20) and the PG3X fan GAF mates it with. As you would expect from GAF, it's well made and appears to be durable. It's about as heavy duty as a pound of aluminum can be made to be. I have every confidence that the vent itself will outlast the house. However.... The instructions that are printed with low-res ink on the outside of the box are perhaps the worst set of directions I have ever encountered anywhere. Doing a retro-install of this gable vent is no different technically than putting a window into an existing wall. You build an outer frame that spans from stud to stud, then put an inner frame inside sized to the rough opening of the vent itself. If you decide to put one of these in and have never done anything like this, buy the vent (don't know how it could be any better) and either read online how to retro fit (plenty of material out there), or better still, get help from someone who knows about framing. Do yourself a favor and don't even look at GAF's instructions. I would have given the vent itself 5 stars, except I penalized them 1 star for the time I wasted trying to figure out what their directions mean. June 6, 2011
Rated 5.0 out of 5.0 by very nice This item was super easy to install. Almost so easy I got confused thinking it couldn't be that easy. on the box is a cut out template. Tape it, level it, draw the lines, cut the wall, and screw the vent into place. That easy. June 18, 2014
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