1.Numeral and color LED display 2.2,3,4,6,8sensors for option description: 1,Numeral and color LED display 2, Step-up buzzer alarm 3 ... from 1.8m to 0.3m 5,Display unit with built-in buzzer 6,2,3,4,6,8sensors for option7,Display size: 132 ... *25*22mm 8,Wireless between display and control ...