This door alarm is made of plastic material, which can withstand use. Features the plastic material, which has high durability, not easy to deform. Fine workmanship, ensures practicality. Features -Color:White -Material:Plastic -Size:7.00X2.50X2.00cm/2.75X0.98X0.79in -Size:4.40X1.50X1.00cm/1.73X0.59X0.39in -Input voltage: DC3V LR03 -Static current: <=35uA -Alarm current: <=135mA -Low voltage: <=2.4V -WiFi: 802.11 / distance: <=20mm -Light range: 0~10000Lux -Operating temperature: - centigrade~+50 degree centigrade -Working humidity: Max 95%RH - Easy to install, easy to install by adhesive, stick it on the window or door, the main unit is horizontally opposite to the strip. - Sound and light alarm, this sensor window and door alarm is loud enough to detect entry and keep and out of the house, protecting your home or office whether you're at home or out. - It is perfect for home, office, shop, garage, dorm, apartment or even RV. - Once and are opened, the alarm is triggered immediately to protect the safety of the family. - It is manufactured with professional technology to ensure the product can work for a long time. Package list: 3 x set of sensor