Three foot section of fiberglass steam pipe insulation for 1-1/4" iron pipe, with 1" wall thickness and factory applied aluminum jacketing (white, reinforced covering). Sections are spilt lengthwise and feature an adhesive strip to seal the split after installation. These fiberglass steam pipe insulation sections are rated -20°F to 500°F. Oversize shipping charges apply and insulation may take up to three business days to ship. To determine the measurements of the insulation, measure the outside diameter of your pipe and then reference the chart below. Please note that there is always a small margin of allowance with pipe sizing.