Feature: 1. Efficient Alarm: Even a slight vibration can trigger the alarm, more sensitive, can be a good protection of your property and items. 2. Wide Application: Wired rolling shutter door magnetic alarm can be used for different types of doors such as rolling gates and rolling shutter doors. 3. Easy Installation: No need for complex circuit connection, just simple installation can be enabled, providing you with convenience. 4. Strong Adsorption Force: The magnet end uses strong magnetic glue, and the induction is more sensitive. 5. Anti Theft Function: Effectively prevent theft and intrusion, to protect the security of the home and the store, is a very practical tool. Specification: Item Type: Door Magnetic Contacts Switch Sensor Weight: 168g/5.9oz Sensing Distance :50-70mm/2-2.8in Material: Aluminum alloy silver gray plating Suitable for Working Voltage: 12V Applicable to Working Current: ≤500ma Contact Mode: (NC\NO) Normally closed Installation Mode: buried, surface installation Scope: Applicable to all kinds of rolling shutter doors. Package List: 1 x Magnetic Contact Switches 4 x Screws 1 x Accessory