hmm didnt see that. So maybe im wrong, but i dont like how they present it
it says
"Ultimate kit to make your Traxxas E-Maxx scream! All you need is a power supply for the charger a lipo cutoff for your ESC and you're ready to run."
then it says
"40+mph in most brushless setups(7.4 Volts)"
then
"equires E-maxx Tray Expansion Kit (#3927X) to fit"