... switch:on/off 2.Display size: 96*27*20mm description: 1,Numeral and color LED display 2, Step-up buzzer alarm 3,Left and ... right obstacle indication 4,Numeral display from 1.8m to 0.3m 5,Display ... unit with built-in buzzer 6,Buzzer alarm switch:on/off 7,2,3,4 sensors for option8,Display ...