Huawei W1 Quick Start Manual page 20

Operating Environment
> Do not use or charge the device in dusty, damp, and dirty places
or places with magnetic fields. Otherwise, it may result in a
malfunction of the circuit.
> The device complies with the RF specifications when the device is
used near your ear or at a distance of 0.59 inch (1.5 cm) from your
body. Ensure that the device accessories such as a device case
and a device holster are not composed of metal components. Keep
your device 0.59 inch (1.5 cm) away from your body to meet the
requirement earlier mentioned.
> On a stormy day with thunder, do not use your device when it is
being charged, to prevent any danger caused by lightning.
> When you are on a call, do not touch the antenna. Touching the
antenna affects the call quality and results in increase in power
consumption. As a result, the talk time and the standby time are
reduced.
> While using the device, observe the local laws and regulations, and
respect others' privacy and legal rights.
> Ideal operating temperatures are 32 °F(0 °C) to 113 °F(45 °C).
Ideal storage temperatures are -4 °F(-20 °C) to 158 °F(70 °C).
Extreme heat or cold may damage your device or accessories.
Prevention of Hearing Damage
Using a headset at high volume can damage your hearing. To reduce
the risk of damage to hearing, lower the headset volume to a safe and
comfortable level.
Safety of Children
Comply with all precautions with regard to children's safety. Letting the
child play with your device or its accessories, which may include parts that
can be detached from the device, may be dangerous, as it may present a
choking hazard. Ensure that small children are kept away from the device