NOYAFA NF-268 - Manual (Page 9)

Your excellent helper in cable test! 6
3.7 Unique function
When users have targeted the network cable, at this time, he can
directly insert the cable into RJ45 port of receiver to check its wiremap.
If leds No.1-8 is on, it means the cable is normal. If not, the cable is
abnormal. The details can be read from Chapter 3.6.
Other functions:
(1) Low-voltage hint function
When the battery voltage is low(＜6V)
， push the function button to
“scan” or “test” , at this time, both the scan indicator and wire sorting
indicator will flash, which means the battery should be replaced.
(2) Earphone function
The earphone can be worn in noisy environment for operation so as
to avoid external interference.
(3) Volume adjustment function
Turn volume adjustment switch on the receiver when tracing cable to
adjust the volume to the appropriate degree.
(4) Floodlight function
The side floodlight can be started at night or in dark.
The floodlight turns on so as to facilitate your normal operation.