A jet nozzle for use in propelling a trolley or sledge provided with a television or video camera along a conduit, such as a sewer, for use in inspecting the interior of the conduit, the jet nozzle comprising a casing having an end wall provided with a plurality of discharge openings communicating with a chamber formed between said end wall and a transverse wall, an inlet in communication with the chamber and connected to a home, a bearing provided on the casing mounting a connector member for connecting the jet nozzle to the trolley or sledge and allowing the casing to rotate relative to the connector member.