Two-way Talk Function: With built-in high sensitive microphone and speaker for two-way talk. You can hear your baby's voice clearly and use your voice to comfort her/him instantly when they are crying. Easy to Use: The volume of parent unit and baby unit can be adjusted freely by pressing the left or right button, and both have power switch  to turn off the baby monitor to save power when not in use. Convenient to Carry: The parent unit has a backside clip, which allows parents to carry it conveniently when doing some housework, very considerate design. Dual Power Supply Ways: The parent unit and baby unit both can be powered by 3 * AAA batteries(not included) or DC 5V 1A power adapter(included), more flexible to use. Specifications: Transmission Frequency: ISM 2400-2483MHz Transmission Power: 17dBm Modulation Type: FSK Transmission Range: 150-200M in open area, indoor range depends on actual environment Power Supply: 3 * AAA batteries(not included) or DC 5V power adapter(included) Power Consumption: 70mA Operating Temperature: -10℃ to 60℃ Item Size: 6.2 * 4 * 10.3cm/ 2.4 * 1.6 * 4.1in(baby unit); 6.2 * 4.5 * 10.3cm/ 2.4 * 1.8 * 4.1in(parent unit) Item Weight: 75g/ 2.6oz(baby unit); 78g/ 2.8oz(parent unit) Packing List: 1 * Parent Unit 1 * Baby Unit 2 * Power Adapter 1 * Users Manual(English)