This product is small in size and easy to carry. It will not be a burden for the elderly or children. It will dial your telephone number or mobile number if there is voice higher than 45bD in 4 meters.Features:Excellent stand by and working time.Prominent sound quality makes it more reliable.Built in 2 mic, can be heard clearly.Automatic monitoring function: as long as it exceeds 45 decibels in 4 meters, it will automatically call back.Super mini size, easy for carrying.Specifications:Card compatible: GSM / SIMMicrophone Range (meter): 5-7 RadiusReceive sensitivity: about 10K GPRSWorking temp: -40 to 50Responding frequency: 1.2K-800KhzStand-by time: 3-5 days (without voice control), 10-15 days (without voice control)Work frequency: 850MHz, 900MHz, 1800MHz, 1900MHz (please check if it can work with your local system format before purchasing)Battery: 1 * 3.7V, 300mAh Li-ion batteryItem size: 35 * 20 * 14mm / 1.4 * 0.8 * 0.6inItem weight: 25g / 0.9ouncePackage size: 60 * 60 * 30mm / 2.4 * 2.4 * 1.2inPackage weight: 25gPackage list:1 * Voice System1 * USB Cable1 * User Manual