It turns off the sensors inside the car when you alarm it. Ie if you left the dog in back and need to stop off at a cash point you'd lock the car but don't want him to set off the alarm you'd hit that button before getting out!
Its a pile of poo, I mean mine broke off and is made from cheap plastic. Totaly crap.
I have a clifford G5 Alarm so i dont need to use it anyways. Would also like to no were to get a new from as i got a hole there now..
Look under your seat and see if its wondering around there somewhere! Mine was missing when i bought the car and 3 months later i found it behind my drivers seat just underneath! lol
if you left the dog in back and need to stop off at a cash point you'd lock the car but don't want him to set off the alarm you'd hit that button before getting out!