Lexus ES300 Owner's Manual page 26

KEYS AND DOORS
NOTICE
D Do not let the key case become bent as the key plate
may fall out or become bent also.
D The flat key is designed for emergency use only. So
do not use it regularly instead of other master keys.
12
When using a key containing a transponder chip,
observe the following precautions:
D When starting the engine, do not use the key with a
key ring resting on the key grip and do not press the
key ring against the key grip. Doing so may prevent
the engine from starting, or may cause the engine to
stop soon after it starts.