Strong penetration, no need to worry about not receiving the signal Blue LED light: Unique blue LED light design, flashes after ringing. Sturdy and durable, safe to use Product features: Use solar transmitters to save energy; energy saving is durable Open space battery life: maximum 300M 4 adjustable volume levels, 38 different melody styles to choose from. A transmitter can be paired with multiple receivers. One receiver can also be paired with multiple transmitters. Receiver Working voltage: 90-260V Power consumption: 2W Note: The data are all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, the actual object received shall prevail.