If you look at the bottom of the ad, it doesn't say anything about voltages but it does list input/output. It says UK/UK and USA/USA. I can't figure out what that would mean if it didn't mean voltage.
I did look at the PDF manual and the user's guide in the package. Not a word about voltages anywhere.
And you're right. It seems to mean the thing is worthless.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13