Features: 1.Theclosertheobstacleis,thefasterthealertbeepingfrequencyistoindicatethesafetyzone,cautionzoneanddangerzone 2.4-levelsoundtoreminddistanceofthebarrier 3.Thesystemwillautomaticallystartupwhenreversing 4.Twoorfoursensorsforoption Technicalparameters: 1.Operatingvoltage:12VDC(24Vavailable) 2.Operationcurrent:20mAh 200mAh 3.Sensorinstallationheight:45 60cm 4.Detectiondistance:0.4 1.8m 5.Ultrasonicfrequency:40kHz 6.Operatingtemperature:-40°C +85°C 7.Beepvolume:80 100dB(at30cmdistance)