Portable 2.4GHz Wireless Digital Audio Baby Monitor One-Way Talk Crystal Clear Baby Cry Detector Sensitive Transmission: Built-in MIC and speaker for one-way audio monitoring, with nightlight function.Adopt frequency hopping spread spectrun (FHSS), -interference and sound clarity2.4GHz digital wireless transmission, stable transmission signal.Position the transmitter at a distance of about 1.5-2.0 meters from the baby.Open space transmission range to 250M.High sensitivity, the crying voice is easy to be heard and to inform parents. Specifications: Operating Temperature range: -10°~+60° Transmission Frequency: Ism 2400-2480MHz Modulation Type: FSK Material: Power Supply: Built-in lithium battery Package Weight: 212g / 7.5oz Baby Unit: 13 * 9.7 * 3.5cm Storage Temperature: -40°~+70° Parent Unit: 13 * 9.7 * 3.5cm Transmission Power: 17dBm Package Size: 14 * 10.5 * 10cm / 5.5 * 4.1 * 3.9in Package List: 1 * 1 * User Manual (English) 1 * Receiver 2 * Power Cable Open space transmission range up to 250M. Adopt frequency hopping spread spectrun (FHSS), Anti-interference and sound clarity. Built-in MIC and speaker for two-way audio monitoring, with nightlight function. 2.4GHz digital wireless transmission, stable transmission signal. Position the transmitter at a distance of about 1.5-2.0 meters from the baby.