Item Type: Door Magnetic Contacts Switch Sensor_x000D_Weight: 168g/5.9oz_x000D_Sensing Distance :50-70mm/2-2.8in_x000D_Material: Aluminum alloy silver gray plating_x000D_Suitable for Working Voltage: 12V_x000D_Applicable to Working Current: 500ma_x000D_Contact Mode: (NC\NO) Normally closed_x000D_Installation Mode: buried, surface installation_x000D_Scope: Applicable to all kinds of rolling shutter doors 1Efficient Alarm: Even a slight vibration can trigger the alarm, more sensitive, can be a good protection of your property and items. 2Wide Application: Wired rolling shutter door magnetic alarm can be used for different types of doors such as rolling gates and rolling shutter doors. 3Easy Installation: No need for complex circuit connection, just simple installation can be enabled, providing you with convenience. 4Strong Adsorption Force: The magnet end uses strong magnetic glue, and the induction is more sensitive. 5Anti Theft Function: Effectively prevent theft and intrusion, to protect the security of the home and the store, is a very practical tool. 1 xMagneticContactSwitches 4 x Screws 1 x Accessory