Feature:1. 2.4GHz digital wireless transmission, stable transmission signal.2. Built-in MIC and speaker for two-way audio monitoring, with nightlight function.3. High sensitivity, the crying voice is easy to be heard and to inform parents.4. Adopt frequency hopping spread spectrun (FHSS), Anti-interference and sound clarity.5. Position the transmitter at a distance of about 1.5-2.0 meters from the baby.6. Open space transmission range up to 250M.Specification:Transmission Frequency: 434.125MHzTransmission Power: 10dBmModulation Type: FSKPower Supply: Built-in lithium batteryOperating Temperature range: 0~50Storage Temperature: -40~+70Material: plasticBaby Unit: 13 * 9.7 * 3.5cmParent Unit: 13 * 9.7 * 3.5cmPackage Size: 14 * 10.5 * 10cm / 5.5 * 4.1 * 3.9inPackage Weight: 212g / 7.5oz.Package List:1 * Transmitter1 * Receiver2 * Power Cable1 * User Manual (English)