PARKING SENSOR SYSTEM: VFD DISPLAY PARKING SENSOR Item No. Number of sensors Alarm Voice Remark SB-D810 2 BiBi / human voice 2 rear sensors SB-D811 4 BiBi / human voice 4 rear sensors SB-D812 6 BiBi / human voice 4 rear sensors, 2 front sensors SB-D813 8 BiBi / human voice 4 rear sensors, 4 front sensors