Geo 1995 Prizm Owner's Manual page 52

One key is used for the
ignition, the doors, and all
When a new Prizm is delivered, the dealer removes the
metal plate from the key ring and gives it to the first
owner.
The metal plate has a code on it that tells your dealer or
a qualified locksmith how to make extra keys. Keep the
code in a safe place. If you lose your keys, you'll be able
to have new ones made easily using this code.
I
NOTICE:
Your Geo has a number of features that can help
prevent theft. But you can have a lot of trouble
getting into your vehicle if you ever lock your
keys inside. You may even have to damage your
vehicle to get in. So be sure you have an extra
key.
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