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Master Flow

Model # F6IFD8X300

Internet # 100396936

Store SKU # 685764

8 in. x 25 ft. Insulated Flexible Duct R6 Silver Jacket

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

$30.98 /each
  • R6 fiberglass insulation for greater insulating power
  • Duct can be cut to length as needed


Model # F6IFD8X300

Internet # 100396936

Store SKU # 685764

Store SO SKU # 755578

The Master Flow 8 in. x 25 ft. Insulated Flexible Duct R6 Silver Jacket is used in standard Heating and Air Conditioning (HVAC) systems and some venting applications. The duct has R6 insulation which contains 33% more insulation than the standard R4.2 product. This additional insulation provides greater thermal efficiency to save energy. The product is also covered in a heavy duty, silver jacket for durability. The duct is ETL listed, meeting the UL181 standard.

  • Flexible duct is convenient for use in multiple applications including heating & A/C systems and some venting
  • Oversized core to connect quickly and easily to standard sheet metal fitting
  • Galvanized core wire for greater corrosion resistance vs. non-galvanized wire
  • Insulated duct features a maximum temperature rating of 200 degrees Fahrenheit
  • Always install per instructions and seal using approved mastic or sealant (or approved tape)

Info & Guides

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Product Depth (in.) 
Product Diameter (in.) 
8 in 
Product Height (in.) 
Product Length (in.) 
300 in 
Product Width (in.) 
Silver Jacket 
Insulator material 
Maximum air flow (CFM) 
R Value 
Warranty / Certifications
Certifications and Listings 
2-UL Recognized,ETL Listed 


Rated 4.7 out of 5 by 11 reviewers.
Rated 5.0 out of 5.0 by Finally got my cool room! In a recent room addition to our home, we noticed the new room was not cooling as well as the others. They had added a 6 inch flex duct to the new room, while all the others in the house were 8 inch. My husband and I went to Home Depot to see what our options were to improve air flow to the new room. A wonderful employee, Danny, soon greeted us and recommended we change the flex duct to an 8 inch. He helped us select the products that we would need including the 8 inch flex duct. I installed the new duct and could immediately feel the difference in air flow. I now have a "cool" new room! July 28, 2014
Rated 5.0 out of 5.0 by Excellent product I was a bit wary of flexible ducting as some of the existing, older, flex duct in my attic was torn and crushed. I had intended to replace this with round metal duct and then insulate the outside of it. However, I spoke to a friend in the HVAC business and he said that flex duct is now the standard for short (less than 12 ft.) runs. He said that it is actually fine for longer runs provided it is run straight and pulled taut to remove slack. Armed with this advice I purchase some of the 8 in. duct. The installation was a snap - took me about 15 minutes. It would have taken me at least 2 or 3 hours to run and insulate metal duct. Provided you use zip ties and plenty of foil tape at your connections, this product is very sturdy and effective. I intend to replace my remaining round ductwork with this product prior to having my attic insulated with blown-in insulation. October 1, 2009
Rated 5.0 out of 5.0 by Flexible and easy to use I used various sizes of Master Flow Flexible ductwork when installing my furnace. The 8 inch ductwork is as tough and flexible as the 12 and 7 inch sizes. When installing this ductwork on Master FlowStarting collars, installation is fast and very secure. The ductwork is very flexible and able to snake through tight spaces. I definitely recommend this ductwork. September 29, 2013
Rated 5.0 out of 5.0 by Great product just needs to be offered in shorter lengths I am happy with the product but disappointed I couldn't buy it in shorter lengths. I recently did a remodel and needed to move an HVAC line. This required an 8ft length to be added for a reroute. Unfortunately I could only by 25 foot sections at 60.00 a pop. I understand a HVAC company or wholsaler not offering shorter lengths but Home Depot is said to cater to the home owner, which I am. I wasn't to thrilled spending so much for a section I have seen a hundred times in a dumpster after a new build. Homedepot please consider selling more reasonable quantities. Product great but way more than I needed. I recommend you do the same as you do for wire spools, charging a premium for smaller rolls. You can still make your money and I can still save mine. January 14, 2014
Rated 5.0 out of 5.0 by easy to use I saved over $60 buying this online and having it delivered than if I had bought it locally in our small town. It is as described and worked as expected, who could ask for anything more? It was fun opening it up as it was packed tightly in a box like a slinky and came out like a Jack in the box. October 28, 2014
Rated 5.0 out of 5.0 by Great product! This is the best 8" duct I could find out there. It has the best R value and the material it's made of is strong. I strongly recommend this product. November 13, 2010
Rated 5.0 out of 5.0 by this product worked as advertised. this was easy to install,and has worked well with no issues. May 13, 2014
Rated 5.0 out of 5.0 by good stuff! Works great and doesn't leak any heat from it. Easy to run and cut. Can't complain what so ever. March 19, 2014
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