S4 works as radio earpiece receiver / radio guide receiver for the listener.
It is a very economical model in our product range,
being the smallest and lightest earpiece receiver of all our models.
Matched with 310L (radio transmitter).
Frequency range: 2.4 Ghz; size: 35*16*10mm; weight: 12g; channel number: 99CH
Effective working distance: 150m; working time: 10 hours
Battery: lithium polymer battery; charging method: charging base and USB cable.
Accessories: lastic hook and plastic covering