gps tracker gsm the listening device alarm s py gadgets mini b ug bike car tracker smart tag tracking dog quad band 850/900/1800/1900mhz

2. very easy to operate: just make a call to the sim number which is installed in the device you will can hear nearby voice within 10 meters in a few seconds. 3. gsm quad band (850/900/1800/1900mhz), can work perfectly around the worldwide. 4. built-in 2 mic to ensure the good sound quality, prominent sound quality makes s py more reliable 5. supports pre-setting number, telephone number and mobile number both are ok. long standby time: built-in 200ma backup battery, it can last around 3-5 days under acoustic alarm function on mode. it can last around 12-15 days under acoustic alarm function off mode..syi