Double walled CNT is an emerging class that consists of two concentric carbon nanotubes. They also possess increased mechanical strength and thermal stability with increased electronic and optical properties. It also has the capability to become novel sensors and to be used in electronic devices. Which exhibit various other properties, including improvement in a lifetime and current density for field emissions. They are highly stable against aggressive chemical, thermal and mechanical treatments. Their applications include its use in conductive plastic parts, parts of aircraft, anti-static fuel hoses and electronics, etc.