Product: Boots Boots Underground Preinsulated Duct System Center Saddle Boot ITEM#SizeBoot SizeFits on PipePDFDWG 08-25708” [203 mm]4" x 12" [102 x 305 mm]8” [203 mm] 10-257010” [254 mm]4" x 12" [102 x 305 mm]10", 12", 14', 16", 18" [254, 305, 356, 406, 457 mm] Offset Saddle Boot ITEM#SizeBoot SizeFits on PipePDFDWG 10-255010” [254 mm]4" x 12" [102 x 305 mm]10” [254 mm] 12-255012” [305 mm]4" x 12" [102 x 305 mm]12", 14', 16", 18" [305, 356, 406, 457 mm] 12-2551 12” [305 mm]4" x 24" [102 x 610 mm]12", 14', 16", 18" [305, 356, 406, 457 mm] 90° Boot ITEM#SizeBoot SizePDFDWG 08-25028" [203 mm]4" x 12" [102 x 305 mm] 08-25038-3/4" x 8" Round [222 x 203 mm] 16″ Boot Extension ITEM#SizePDFDWG 20-00504" x 12" x 16" [102 x 305 x 406 mm]