813R works as radio / audio receiver.
Matched with 813T (transmmitter).
①/② : Change channel
③/④ : Change volume
Carrier Frequency: UHF 600MHz-900MHz (customized); channel numbers: 18 - 200 channels
Working time: 20 hours; battery: lithium polymer battery
Charging method: charging base and USB cable.
Working distance: >150m; machine size: 86.5*48*18mm; machine weight: 50g
Accessories: earphone and hanging rope