anyone use this [link=http://www.rc-fans.com/details.asp?prodid=1806]kill switch[/link] ?

it seems it can be used directly between the battery and the ignition,with less than 6 Volts.

opto switch from Hobbyking needs 6V and up,which makes this perfect for a 4.8V single battery setup.

i wonder if others have that 6 volt limitation too.