Denso BHT-M70 Series Operator's Manual page 6

Chapter2 Component and Functions
2.1 BHT-M70
Upper side
Lower side
6
Receiver,Speaker
Status indicator
microphone
USB connector
Interface connector
Hand belt
Rear camera
Code reading window
Battery cover locks
M1 key
M2 key
Left trigger key
Power key
M3 key
M4 key
Right trigger key