Yes, those are cheap packs, if you are going to do club racing and some more, you will need better packs, but if you plan on just basing/personal use, then they are ok.

A cutoff is a electronic devite that is between the battery and the set of (10) #1157 autmotive bulbs for discharing, It stops the discharge once the packs gets to 5.4 volts... or .9 volt per cell. Keep the pack from dischargin anymore.