Product Description
Mica tubes are made of layered mica and can either be machined or

 unwrapped to fit. Mica tube includes two species: 

(1) Muscovite mica tube: Silver color, Heat resistance: 500 degree centigrade

(In constant operation), 1000 degree centigrade (in intermittent operation). 

----Diameter: 8mm, 10mm, 15mm, 50mm, 100mm, 200mm, ...300mm 
----Length: 10mm, 20mm, 50mm, 100mm, 300mm, 500, ...1100mm