Features: 1) Compatible with 2, 3, 4 sensors 2) 3-grade Bi-Bi sound in different sections 3) Automatically starts after turning on the power 4) Bionic detecting-head design to measure accurately, quality guarantee 5) Available for 2~4 sensors of embed or adhesive, many colors Specifications: 1) Working voltage: DC12V±2V 2) Max. power: <5W 3) Working temperature: -20 ~ 60oC 4) Display distance: ≤1.8m 5) Alarm distance: ≤1.5m 6) Alarm loudness: ≥50dB Outer packing: 10pcs/ctn Carton dimensions: 34 x 21.5 x 39.5cm