This straight register boot is used to make a duct transition from round pipe or flexible duct to register or vent grille. In addition, it serves as a versatile connector for exhaust fans, range hoods, dryer vent covers, and HVAC system. Its unique air leak proof and space saving design makes it a good choice for ventilation projects, ensuring enhanced ventilation efficiency.Specification:Color: Silver Tone;Material: Galvanized Iron;Total Size: 205 x 152.4 x 210mm / 8.07 x 6 x 8.27 inch (L*W*H);Rectangular Interface Size: 205 x 101.6mm / 8.07 x 4 (L*W), fits 4 x 8 inch register or grille.Round Interface Outside Diameter: 101.6mm / 4 inch;Thickness: 0.6mm / 0.02 inch;Packing List: 1 x HVAC Duct Pipe Transition FittingAdvantage:Crafted from a galvanized plate, this transition is longevity and reliability.