Ive no idea mate, it doesnt specify.
One of the things I like about this one is its rechargeable, so you dont need to apply power to it, thus I can just sit it an the dash on an anti slip mat and off we go.
No messing about with trailing power leads etc.

Ive just downloaded a vbox data file from a circuit racing website and one of the users has created this great website where you port in your datafile: http://www.vboxtools.com/
And it spits out all the data you can imagine from the runs.

Fascinating kit - looking forward to mine arriving.