Hello Lytherm gasket material is good to 1,000 Deg or so. That is why Wood Pellet Stove makers use Lytherm. However you do not have to pay $20 to $30 for one gasket when you can make your own gaskets much cheaper. Example: You can get 4 -- 5-3/4 inch gaskets on one sheet! That is $1.75 per gasket! YEA ! ! You can get the Lytherm gasket Material sheets from Brunner's Bits and Pieces or E-Bay or Wood Heat and Solar for approx. $7.00 Wow $7.00 per sheet here from Brunner's Bits and Pieces! http://heiligkuh.com/bbandp/product_info.php?products_id=51&osCsid=7c946df252383294e8515661e3ffd948 Wood Heat and Solar $18.00 per sheet http://woodheatstoves.com/lytherm-gasket-by-square-foot-raw-material-p-12444.html E-Bay http://www.ebay.com/itm/Pellet-Stove-Gasket-Material-1-8-thick-/190652779019?pt=LH_DefaultDomain_0&hash=item2c63ca8a0b Here is how I did. I made a Template. You can use paper or cardboard, or posterboard. I used cardboard here. 1. Measure the outside diameter of the Combustion Blower and divide by 2 for the compass setting. Example: 5-3/4 inches so half is 2-7/8 inches 2. Set the compass to 2-7/8" and draw a circle on the template. 3. Cut out the circle. 4. Reduce the compass setting by 1/2" and draw the inside circle. 5. Cut out the inside circle 6. Put on the blower, check for fit (Trim if needed) and mark bolt holes with felt tip maker, pen or pencil. 7. Use a paper punch to punch out holes in template for bolt holes. 8. Trace template on to one corner of Lytherm Sheet 9. Cut out template 10. Punch holes Easy Peasy and $ave some money! Do not worry if it does not come out 100% perfect, it does the job! See pics below!