Sony Xperia X Manual page 45

Always keep your ear some distance from Speaker while ringtones, music or other handset
sounds play.
If it sounds in excessive volume, ears or hearing may be damaged.
Watch TV from a distance in good light.
Failure to do so may impair vision.
Moderate handset volume when using Headsets.
Prolonged use and excessive volume may damage ears or hearing.
Desktop Holder (Optional Accessory), AC Charger
(Optional Accessory)
Do not cover/wrap with cloth or futon while charging.
Heat may build up resulting in fire, burns, malfunction, etc.
Use specified power supply and voltage.
Failure to do so may cause fire, malfunction, etc.
AC Charger: 100 V to 240 V AC (household AC outlet only)
Do not use commercially available voltage converters, as when traveling. May cause fire, electric
shock or malfunction.
Unplug AC Charger power plug when you do not use it.
Adhering foreign substance or liquid to AC Charger power plug or stomping AC Charger power plug
may cause electric shock, fire or malfunction.