It's a four pole 3.5mm jack socket. You need a four pole jack plug to three phono socket lead to connect to the recorder. One phono will be video and the other two stereo audio (left and right)
By convention the phonos are coloured yellow for video, red for right audio and white for left audio. However not all leads are wired the same, which seems to catch out a few NowTV users from what I've read on the interweb.
So you may have to experiment a bit by trying the yellow plug in the video input of the recorder (leave the other two plugs disconnected for now) and see if you get a picture.If not unplug it and try the red, if that does not work try the white. Once you have identified the video connector plug the other two into the audio sockets. If the video is not on the yellow you may have to do a few listening tests to determine which is left audio and which right.