No idea, ask them if
a) it stops the engine
b) it has alternator protection so can be used as an engine off switch
Cheap ones don't stop the engine and could blow up ones alternator. Anyone used to preparing race cars should get it right, although most race scrutineers can tell tales of battery isolators that didn't stop the engine.
What you want is:
The right battery isolator and not:
The wrong battery isolator 
