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IMPERIAL 4-in to 3-in Plastic Round Duct Reducer

Name: IMPERIAL 4-in to 3-in Plastic Round Duct Reducer
Brand: IMPERIAL
SKU: 3134579
Price: 3.98 USD
Availability: InStock
Rating: 3.7 (28 reviews)

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3.7

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Tomorrow

30 available

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Thu, Oct 8

44 available

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This Imperial 3-in to 4-in Increaser allows you to easily adapt a 3-in bathroom fan exhaust port to a 4-in flexible duct. A quality product, the increaser is made from sturdy polystyrene for lasting performance, and is quick and easy to install.

Ideal for bathroom fan exhaust applications
Adapts a 3-in fan exhaust port to a 4-in flexible duct
Durable polystyrene construction for lasting use
Quick and easy to install

General
Type	Duct reducer	Package Quantity	1
Material	Plastic	Shape	Round

Dimensions
Diameter End 1 (Inches)	4	Length (Inches)
Diameter End 3 (Inches)	0	Width (Inches)
Diameter End 2 (Inches)	3	Depth (Inches)

Features
Crimped	No	Insulated	No
Damper Included	No	Flange Included	No
Gauge	0

Certifications
CA Residents: Prop 65 Warning(s)	No	Safety Listing	Not safety listed

Warranty
Warranty	1-year limited

Miscellaneous
UNSPSC	40141900

Check out the Best Selling Duct Transitions & Connectors on Lowes.com

Review

3.7 out of 5

28 Reviews

71% Recommend this product

Ratings may include incentivized customer reviews.

28 Customer Reviews

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4" to 3" adapter.

Would Recommend

I can't buy this anywhere else.

Exhaust fan adapterSeptember 23, 2026
Verified Purchaser

Was this Review Helpful ?

Works!

Would Recommend

Was used for a flow system for outdoor run off.

JennsueSeptember 17, 2026
Verified Purchaser

Was this Review Helpful ?

extension

Would Recommend

It did not fit my application

hossJune 26, 2026
Verified Purchaser

Was this Review Helpful ?

Works great

Would Recommend

Works great

JrowleyJune 19, 2026
Verified Purchaser

Was this Review Helpful ?

There always a way to make th8ngs work

Would Recommend

Its was perfect fit for my application

HelperMay 3, 2026
Verified Purchaser

Was this Review Helpful ?

Simple reducer

Would Recommend

It is what it is supposed to be. Good price

MichaelDApril 19, 2026
Verified Purchaser

Was this Review Helpful ?

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COMPARE PRODUCTS

		Name	Current Item IMPERIAL4-in to 3-in Plastic Round Duct Reducer
		Ratings	28
		Diameter End 1 (Inches)	4
		Type	Duct reducer
		Width (Inches)	0
Lambro4-in to 3-in Plastic Round Duct Reducer	IMPERIAL4-in to 3.0-in 30 Gauge Galvanized Steel Round Duct Reducer	IMPERIAL6-in to 4-in 30 Gauge Galvanized Steel Round Duct Reducer	IMPERIAL4-in to 4-in 30 Gauge Galvanized Steel Round Duct Elbow	Lambro4-in to 4-in 30 Gauge Galvanized Steel Flexible Duct Connector	IMPERIAL4-in to 4-in 32 Gauge Galvanized Steel Round Ductboard Duct Starting Collar	IMPERIAL5-in to 4-in 30 Gauge Galvanized Steel Round Duct Reducer	IMPERIAL4-in to 4-in Plastic Oval Duct Elbow	IMPERIAL6-in 30 Gauge Galvanized Steel Round End Register Duct Boat
43	117	142	320	158	34	61	99	21
4	4	6	4	4	4	5	4	6
Duct reducer	Duct reducer	Duct reducer	Duct elbow	Flexible duct connector	Duct starting collar	Duct reducer	Duct elbow	Duct boot
4	4	0	0	4	4	0	0	4