1.5 Intelligent Working Modes: 1. **AntiIntrusion Mode**: Triggers a 60s alarm when opened (stops when closed). 2. **30s Continuous Alarm**: Alarm continues even after the door is closed. 3. **Doorbell Mode**: Friendly 6s chime for arrivals. 4. **DoorClosing Reminder**: 180s beeping sound when the door is left open to remind you to close it. 5. **Delayed Alarm**: 8s delay before activation. 2. **Expandable with up to 18 433 MHz Security Sensors and Remotes**: Supports pairing with up to 18 additional 433 MHz sensors (door/window sensor/motion sensor). 3. **Remote Control for Easy Management**: Allows you to arm, disarm, and monitor your door sensor alarm remotely for enhanced security. 4. **Adjustable 120 dB UltraLoud Alarm** Equipped with a powerful 120 dB alarm to deter intruders and alert you instantly. Features adjustable volume settings to suit your needs. Also supports lowvoltage warning.