Description: This set of magnetic detecting switch monitors the opening and closure of doors and windows used to protect doors and windows for the most part. It is great for installed on doors of house, garage, warehouse, enterprise and shop etc.  Specifications: Condition: 100% Brand New Material: ABS Plastic  Color: As Picture Shown Operating Voltage: 1.5VTransmitting Frequency: 433MHzBattery: 1 * AAA Battery(Not included) Battery Life: About 2~3 Year If it is opening and closing 5 times per day Transmitting Distance for Many Main Unit: 100~200m/328.1~656.2ft(open area distance) Size: Approx. 7.3*2.5*1.5cm/2.87*0.98*0.59in, 3.8*1.1*1.1cm/1.5*0.43*0.43inWeight: Approx. 30g Package Included: 1 * Set of Wireless Door Magnetic Detecting Contact with Adhesive Note: 1.Can not used alone. Should work with the alarm system main unit for alarming.2.The indicator light will flash once in every 3 seconds while it is in low battery status Features This is a set of magnetic detecting switch used to protect doors and windows for the most part. Protective device monitors the opening and closure of doors and windows 433MHz transmitting frequency, wireless connection High quality magnetic sensor contacts with strong magnetic, sensitive respond and long durability It is great for installed on doors of house, garage, warehouse, enterprise and shop etc