Model # R5X4

Internet # 100128235

Store SKU # 100552

Store SO SKU # 1000684245

5 in. to 4 in. Round Reducer

$6.65 /each

Frequently Bought Together

Product Overview

The Master Flow 5 in. x 4 in. Round Reducer features hemmed collar edges to offer an improved fit and increased strength. This part connects a 5 in. pipe to a 4 in. pipe in an HVAC system. It is made of 30-gauge, galvanized steel to provide strength and durability. It has a maximum temperature rating of 390°F.

  • Made of 30-Gauge, galvanized steel for strength and durability
  • Connects 5 in. pipe to a 4 in. pipe in an HVAC application
  • Hemmed collar edges designed to offer an improved fit and increased strength
  • Always seal seams with building code-approved sealant or duct tape (not included)
  • Always insulate ductwork for greater system efficiency and comfort (insulation not included)
  • Maximum temperature rating of 390°F, minimum temperature rating of -100°F

Info & Guides

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Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 


Brand/Model Compatibility 
HVAC application 
All HVAC types 
Product Weight (lb.) 
0.45 lb 

Warranty / Certifications

Manufacturer Warranty 
Free from Manufacturer Defect at Time of Delivery. 

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Customer Questions & Answers

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Customer Reviews

Rated 4.7 out of 5 by 9 reviewers.
Rated 5.0 out of 5.0 by Perfect fit for portable airconditioner to dryer vent conversion. I have a portable air conditioner and needed to exhaust the hot air. The hose is 5 inches and most vents are 4 inches. So, I reduced it at the exhaust point into a 4 inch dryer vent exhaust also available here at Home Depot. Works perfectly. Could not ask for more. July 19, 2016
Rated 5.0 out of 5.0 by Just what I needed to install a furnace. This part was just what I needed for a furnace install. June 10, 2014
Rated 5.0 out of 5.0 by round reducer was able to reduce the air flow for my portable air conditioner, hose sent with it was to short to be able to move it around the room for the best air conditioning.worked out very well after i purchased a plastic expando hose from true valve store.Purchased metal clamps also. August 24, 2015
Rated 4.0 out of 5.0 by Well made While not the exact size I needed, it worked well with a bit of duct tape. September 1, 2015
Rated 5.0 out of 5.0 by no leakage fit was fine time saving vent pipe reducer was sturdy makes a neat job. February 10, 2015
Rated 4.0 out of 5.0 by Easy Installation Cheap if you want to save money but is not as durable November 11, 2014
Rated 5.0 out of 5.0 by good material easy to fit whit the existent materials, good material and price September 16, 2014
Rated 4.0 out of 5.0 by Had to return due to wrong size Seemed like a good adapter, but I needed a 3 in X 5 in. a 4x5 didnt do me any good. June 3, 2014
  • 2016-07-29 T14:48:21.196-05:00
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