1/2Pcs Wireless Door & Window Magnetic Alarm Sensor Home Security Safety Anti-theft Remote Control Features Detering thieves effectively by 108dB loud alarm. Great for home, business, apartment, hotel rooms, garage, RV, travel, pool safety and kids safety.No wiring needed, no screws needed. DIY pairing as necessary. More alarms and remotes available for pairing Use the remote control to disarm before entering the door, not to scare yourself, but to scare thieves, remote control operation, convenient and simple One host can learn 8 remotes, and one remote can control multiple hosts 2 AA batteries, standby for one year (batteries are not included) Low false alarm rate: use reed switch + industrial-grade chip and other components Package Include:1Pc/2Pcs*Door Alarm (as your choice) Note: Due to different personal measurement methods, there will be an error of 2-4 cm, please understand Thanks for your support