Standard Size #640 Register Boxes are lined with 1'' Ductliner to provide an R-Factor of R-4. The #640 Register Box is 4'' Tall without Tabs
- Collar Size 4 in
Standard Size #640 Register Boxes are lined with 1'' Ductliner to provide an R-Factor of R-4. The #640 Register Box is 4'' Tall without Tabs