Features: 2.4GHz digital wireless transmission, stable transmission signal. Built-in MIC and speaker for two-way audio monitoring. High sensitivity, the crying voice is easy to be heard and the lamp will turn on to inform parents. Position the at a distance of about 1.5-2.0 meters from the baby. Open space transmission up to 250M. VOX function. with 2-way talk and nightlight function. Specifications: Transmission Frequency: Ism 2400-2483MHz Transmission Power: 17dBm Modulation Type: FSK Power Supply: DC5V Power Consumption: 70mA Operating Temperature : -10°~+60° Storage Temperature: -40°~+70° Material: Baby Unit: 62*40*111mm Parent Unit: 62*45*111mm (with clip) Package Size: 20.5*14.5*9cm /8.1*5.7*3.5in Package Weight: 395g / 13.9oz Package List: 1 * 1 * Receiver 2 * Power Cable 1 * User Manual (English) 2.4GHz digital wireless transmission, stable transmission signal. Built-in MIC and speaker for two-way audio monitoring. High sensitivity, the crying voice is easy to be heard and the lamp will turn on to inform parents. Position the at a distance of about 1.5-2.0 meters from the baby. Open space transmission up to 250M.