This is a magnetic sensing switch set used to protect doors and windows mostly Protective device monitors the opening and closing of doors and windows High quality magnetic sensor contacts with strong magnetic, sensitive response and long durability The wired part often needs to be installed on the fixed door frame, and the corresponding part is mounted in the corresponding place on the door Easy to install and use . A good replacement for the old contacts. Simple to install without hassle Description: This magnetic sensor detector set includes the hardwired part and the matching part, which is ideal for installing on the doors of the house, garage, warehouse, business and store etc. Keep your home safe with this set of door security accessories. Features: This is a magnetic sensing switch set used to protect doors and windows mostly. A protective device monitors the opening and closing of doors and windows. High quality magnetic sensor contacts with strong magnetic and sensitive response and long durability. The wired part must often be installed on the fixed door frame and the corresponding part is mounted at the corresponding place on the door. Easy to install and use. A good replacement for the old contacts. Simple to install with no hassle. Specifications: Condition: 100% Brand New Material: Zinc Alloy Color: As picture shown Rated Voltage: 12V Rated Current: 120mA Sensing Distance: 50~70mm / 1.9~2.7in Package Included: 1*Set of Magnetic Sensing Contacts Note: Cannot be used alone. Should work with main unit of alarm system to alarm.