This set of magnetic detecting switch monitors the opening and closure of doors and windows, primarily used for door and window protection. Suitable for installation on doors in homes, garages, warehouses, businesses, and shops.Specifications: Condition: Material: ABS Plastic Color: As Picture Shown Operating Voltage: 1.5V Built-in Battery: 1 * AAA LR03 AM4 1.5V 800mAh Dry Battery Battery Life: About 8 months Static Current: 10uA Operating Current: 15mA Transmitting Frequency: 433MHz Transmitting Distance: 100m (open area) Door Magnet Detecting Distance: 25~35mm / 0.98~1.37in Wireless Coding Format: Compatible with eV1527 Operating Temperature: -10~40 Humidity: 90%rh Size: As Picture Shown Installation and fixing method: The product is glued, not screwed.Package Included: 1 x Set of Wireless Door Magnetic Detecting Contact Note: Not designed to be used alone. Must be used with an alarm system main unit for alarm functionality.Features: Magnetic detecting switch primarily used for protecting doors and windows. Security device that monitors the opening and closing of doors and windows. Easy to install and use. A reliable replacement for old contacts. 433MHz transmitting frequency with wireless connection. High-quality magnetic sensor contacts with strong magnet, sensitive response, and long durability.