Huawei G2157 User Manual page 18

Operating Environment
Do not use or charge the device in dusty, damp or dirty

places or places with magnetic fields. Otherwise, the circuit
may not function properly.
The device complies with the RF specifications when the

device is used near your ear or at a distance of 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 1.5 cm away from your body
to meet the requirement earlier mentioned.
On a thunder and stormy day, 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 standby
time are reduced.
While using the device, observe the local laws and

regulations, and respect others' privacy and legal rights.
Use accessories authorized by manufacturers. Using

unauthorized accessories will render the warranty null and
void.
Keep the ambient temperature between 0℃ and 45℃ while

the device is being charged. Keep the ambient temperature
between -20℃ to 60℃ for using the device powered by
battery.
Preventing Hearing Damage
Using the receiver, earbuds, headphones, speakerphone, or
earpieces at high volume can result in permanent hearing loss.
Be extremely careful when listening at high decibel levels. Set
the volume to a safe level. If you experience strange sounds in
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