Imperial 3-1/4"x10" to 4" 30 Gauge Galvanized Register Boot. It is for in-line transition from round pipe or insulated flexible duct to a register or grille.
3-1/4 in. x 10 in. to 4 in.
30 Gauge Galvanized
For in-line transition from round pipe or insulated flexible duct to a register or grille.