M1 works as radio earpiece receiver, and M2 works as radio transceiver.
Matched with 60DT (transmmitter+receiver) and 60DTR (transmmitter+receiver).
M1 is used in one way transmission circumstance. And M2 is used in two way transmission circumstance.
They share the same design.
Visitor who holds and presses the white button on the top part of M2 can talk to everyone in the group.
Only one visitor can talk and listen at one time.
The tour guide who holds main transmitter of 60DT can talk and listen all the time.
Working mode: Digital QPSK; frequency range: UHF (customizable); channel number: 44CH
Channel interval: 1MHz; working current: 40 mA
Frequency response range: 20Hz-10KHz; distortion: <1%
SNR: 100dB; output/input interface: built-in speaker; battery capacity: 350mAH
Charging current: 260mA; weight: 17g
Effective distance: 150m; accessories: hook and small covering