Motorola W510 - Manual (Page 104)

102 Safety Information
lights on in the room, take a 15-minute break every hour, and stop
use if you are very tired.
Caution About High Volume Usage
Listening at full volume to music or voice through a
headset may damage your hearing.
Repetitive Motion
When you repetitively perform actions such as pressing keys or
entering finger-written characters, you may experience occasional
discomfort in your hands, arms, shoulders, neck, or other parts of
your body. If you continue to have discomfort during or after such
use, stop use and see a physician.