Master Flow Pre-Insulated Register Box with Installation Rails create a straight (in-line) transition from round pipe or insulated flexible duct to an air register or grill. They arrive ready-to-install, conveniently pre-wrapped in a foam insulation cap. The included Installation Rails attach to the flange or easy attachment to joists or other nailing surfaces. Design saves time during installation and energy without additional sealant or insulation.
- Sturdy galvanized steel construction
- Fits all flexible and rigid 5 in. diameter ducts
- Pre-insulated with R6 - no need to wrap
- Steel structure is air tight- no leaks and no need to seal