The vLocCam2 is a locator configured for use with CCTV inspection cameras (transmitting 512Hz/640Hz location signals) and a range of battery powered Sondes.

Sondes are small self contained transmitters which are pushed through pipes to find blockages or locate the position and depth of the pipe from the surface. Low frequency Sondes - 512Hz or 640Hz will radiate through both plastic and cast iron pipes. Higher frequency Sondes - 8 kHz or 33 kHz - are used mainly for plastic pipes or ducts.

http://www.vloccam.com