HIGHLY SENSITIVE MICROPHONE - The Motorola Nursery AM21 Audio baby monitor has an excellent built-in microphone that picks up every sound with ease. So you won't miss a single sound from your baby. UP TO 300 METERS RANGE - The Motorola Nursery AM21 Audio baby monitor has a wireless connection with a range of up to 300 meters. This means you can use the baby monitor anywhere in the house without losing connection. ECO MODE - The Eco mode of the Motorola Nursery AM21 audio baby monitor reduces power consumption and transmission power. That way, the devices will only connect when the baby makes noises. DECT TECHNOLOGY - With the special DECT technology of the AM21 baby monitor, interference and tap-proof signal transmission is guaranteed. If you exceed the maximum transmission distance, the AM21 will warn you. VOLUME CONTROLS - You can adjust the volume of the base unit using the volume buttons on the Motorola Nursery AM21 Audio Baby Monitor. The range is 1000 feet / 300 meters when there is a clear line of sight between the parent and baby units, Any obstruction between the units will reduce the range significantly, With the parent and baby units placed indoors, the typical range is up to 165 feet / 50 meters