VH-XXX, except that the X11 is quite new so you won't find much about it. I had both, got rid of both, neither up to the job if you have much in the way of high frequency noise i.e. wind etc as they only actively suppress lower frequencies (I know they claim full-spectrum attenuation but look at the graphs). Better are the ANR sets with decent passive attenuation e.g. Sennheiser HMEC 450 (which I bought in the end) or DC10-13X. Of the two mentioned the Bose is probably better unless you want cellphone/MP3 player capability which works well on the X11.