Britton Audio monitor BC50Li

The transmitter and receiver are battery operated.
A lithium polymer battery is used which has no memory effect, i.e. its energy storage capacity is not reduced due to irregular charging or discharging.
Fully digital, interference-free, operating frequency 863 -870MHz.
Outdoor radius: 500m.
Child's room temperature display on the receiver.
Night light lamp on the transmitter.
The out-of-range receiver signals both audio and visual signals.
"Low battery" warning for both transmitter and receiver.
Adjustable microphone sensitivity on the transmitter.
Vibration in the receiver.
"Conversation" function.
Both monitors come with charging stands and rechargeable batteries.