... when accident appened:Special UPS technology, could make the DVR still working 3-5 seconds under cut the external power ... sensor acceleration sensor, velocity sensor, optional features. 4. Support 3G wireless transmission function. All kind of 3g standard, WCDMA, EVDO, TD ... -SCDMA,support WiFi wireless transmission. GPRS, beidou optional feature. 5. Support IP phone ...