Due to its low rate of thermal expansion (the lowest thermal expansion of any known alloy), this controlled expansion alloy is used in measurement and electronic devices where dimensional changes due to temperature must be minimal. Invar is also used in composite molds for the aerospace industry, bimetal thermostats, clock balance wheels, containers and transfer lines for LNG tankers, echo boxes and filters for mobile telephones, electrical circuit breakers & transformers, electron gun components, high voltage transmission lines, laser components, magnetic shielding, radar and microwave cavity resonators, scientific instruments, as well as shadow masks, deflection clips, and electron gun components in CRT applications, and many other applications.