Very cheap and simple way to internally inspect LEV ducts.
Consists of a 2 megapixel camera and cable which connects either to a tablet/laptop or a mobile phone. Download the App and view the duct internals on your Tablet or Phone screen.
Semi-Rigid cable is both stiff and flexible. Camera has integral LEDs on head which is itself 9mm in diameter so easily fits through a standard 10mm Test Point hole in a duct.