Product Features 2 languages to choose, 5 levels of sound volume, adult/ child mode button, daily weekly and monthly self-test, using it while in the bag(don't need to open it), built-in memory, full voice prompt, IPX55 water and dust resistant. Battery Attention After receiving the product, please connect the battery before the machine can be used. To ensure the maximum service life of the battery, our battery is only installed in the battery slot, and the battery plug is not inserted into the machine. After receiving the product, please open the battery cover and insert the battery plug into the machine before starting the machine. Product Advantages: Long service life of main engine (>10 years), long battery life (>5 years), long validity period of pads (60 months), wide range of equipment operating temperature（0­°C—40­°C), storage temperature(without battery): -20℃ to 55℃,short analysis time ( Easy To Use Anyone can use it with simple training, It is suitable for non-professionals to use this product for emergency response before waiting for professionals to come, Increase the chance of success, make full use of "golden 4 minutes",It is very suitable for shopping malls, public transportation, sports venues, families, schools, companies and gyms.