Product Details
Forced Exhaust, Forced Intake, In-line / HVAC / Ductwork
$28.95 – $91.95Price range: $28.95 through $91.95
Estimated Arrival: Tue. Jul 14th - Tue. Jul 21st.
The FAMCO SDB square to round HVAC transition Box – diffuser is designed primarily for use to attach a ceiling register to your air supply, but can be used in many applications that transition a square duct to round duct. Quality constructed from heavy-duty 28 gauge galvanized steel.
Available in a variety of common sizes, see the drop down menu for all sizes available. The FAMCO SDB square to round HVAC transition box is manufactured by FAMCO in the United States and comes with a 1-year warranty against product defects and workmanship. If you have any questions about this product, please refer to the FAQs above or feel free to contact us.
Forced Exhaust, Forced Intake, In-line / HVAC / Ductwork
Based on 110 customer reviews.
Customer Images








Michael Cotton
Picture is with grate over transition box.

Shawn Greaney

David Watson
Well made and dimensions were spot on. Replaced old hood vent, which had a 6" square exit. New vent has 6" round. And slightly offset.

David Watson
Well made and dimensions were spot on. Replaced old hood vent, which had a 6" square exit. New vent has 6" round. And slightly offset.

David Watson
Well made and dimensions were spot on. Replaced old hood vent, which had a 6" square exit. New vent has 6" round. And slightly offset.

David Watson
Well made and dimensions were spot on. Replaced old hood vent, which had a 6" square exit. New vent has 6" round. And slightly offset.

Pat Urlacher
Great product fitment was right on the money.👍👍👍👍







Yes, the "size" selection refers to the round hole size. The "dimensions" selection would be for the square part of the box.
answered on April 19, 2022 verified ownerThese products are currently manufactured in our Meridian, Idaho factory - the sizes we are able to manufacture are those shown in the dropdown menu.
answered on August 30, 2021 verified ownerWe would recommend asking your exhaust fan manufacture for their recommended install method.
answered on August 25, 2021 verified ownerThis is not something that we currently supply or manufacture.
answered on August 25, 2021 verified ownerThis is not a size we are currently able to manufacture, unfortunately.
answered on August 5, 2021 verified ownerSorry, no questions were found
SKU FCA
SKU TR
SKU GPA
SKU IR
SKU FRB
Thank you for taking the time to review the Square to Round Transition Box. We appreciate the 5-star review, Doug!
We appreciate you sharing a review on the Square to Round Transition Box, Robert. Thanks for the 5-star rating!
It’s what I need. Thanks!
Thanks for reviewing the Square to Round Transition Box, Kenneth! We are happy to hear it is exactly what you needed.
Thanks for sharing a review on the Square to Round Transition Box, Douglas!
Thank you for your review on the Square to Round Transition Box, Beth.