1) Artillery component 2) Firearm component
Found on
https://www.crosswordclues.com/clue/thermal-sleeve
A thermal sleeve is a device around the length of a gun barrel of a large caliber gun, typically found on modern tanks. Its primary purpose is to prevent the gun barrel from being thermally distorted due to environmental conditions, especially when the barrel is already hot due to frequent firing. Thermal sleeves were originally simply insulators....
Found on
http://en.wikipedia.org/wiki/Thermal_sleeve
No exact match found.
