I think it is the same as my Fireteam E-Brake.
View attachment 160928
If it is, it is not much of a rear brake. When you use it, it locks up all four wheels making it hard to slide the rear out. But it does stop the car fast as all of the wheels lock up.
It is interesting but was over sold if you ask me. Wish I could modify it to only lock up the rears.