A stove jack allows you to safely extend a stovepipe through the roof or wall of your tent. Our stove jacks are constructed of fire proof 17-ounce [0.48 kg] silicone-coated glass material (18" x 18" [46 cm × 46 cm]) with a solid silicone ring. Stove jacks are temperature rated up to 700°F (400°C).
More photos here.
Question: Why are stove jacks NOT normally made of metal?
A. Metal would be difficult to transport.
B. Metal would conduct heat to the flammable tent fabric.
C. Something else.
To keep your tent from burning. Making the stove jack out of metal, would conduct heat to from your stovepipe. This could cause your tent material to start to burn.
If you look at the description in your link
Our stove jacks are contructed of fire proof 17-ounce silicone-coated glass material (18" x 18") with a solid silicone ring. Stove jacks are temperature rated up to 700°F (400°C).
This material would be fire resistant and is also a poor conductor of heat (unlike metal) which would prevent your very hot stove pipe from accidentally setting your tent on fire.
