... ,3,4,6,8sensors for option description: 1,Numeral and color LED display 2, Step-up buzzer alarm 3,Left and right ... with built-in buzzer 6,2,3,4,6,8sensors for option7,Display size: 132*25*22mm 8,Wireless between display ... and control unit (HY5200L for option)package: Unit Weight: 0.58Kg 20 pcs/ctnN.W ...