Car Alarms: Pursuit I Think, exsists, key ring

Question
I just purchased a 2006 Sierra 3500 and on the key ring there is an odd looking device without any buttons.  It almost looks like a fishing down rigger weight only cylindrical. Thats the best way I can describe it. Can you tell me what it is and if I am missing any parts. Thank you for your help. Ric

Answer
Not sure exactly, but is sounds like a key chain "proximity" fob.
If you do not have it on the key ring, and not within sensing
range, you maight not be able to start the car.

Test: Leave it inside on the table, then go try to start
the car. It also may unlock and lock the doors when
you get close to it, or leave. so Have the key ready,
and or remote if one exsists.

Without inspection though, just spit balling here....


ALARMTEK