One-way Communication The parent unit can be activated by baby's crying and parents can check the signal status via the indicator lights, so that dad or mom can go to comfort baby in time. Easy to Use The volume of parent unit and baby unit can be adjusted freely by rotating the gear, and both have switch to turn on/off the baby monitor and select channels, easy to use. Convenient to Carry Backside clip design allows parents fix the parent unit to pocket stably when doing some housework, very convenient to monitor baby status anytime anywhere. Battery Powered Design The parent unit and baby unit both can be powered by 3 * AAA batteries(not included), low power consumption and long working time. Specifications: Color: White 43; Yellow Channel: 2 Transmission Range: 100M in open area, indoor range depends on actual environment Power Supply: 3 * AAA batteries(not included) Packing List: 1 * Parent Unit 1 * Baby Unit