Motion-Activated Doorbell – Infrared sensor detects movement up to 110° horizontal, 60° vertical; alerts you to visitors or activity at entryways, driveways, or hallways Wireless Home Security Alarm – Operates in voice, music, or alarm mode; ideal for homes, offices, or shops needing instant notification without wiring or installation Customizable Sound Settings – Choose from 32 built-in chimes; adjust volume across 4 levels (85dB±5dB) for clear audio suited to indoor or outdoor environments Battery-Powered Design – Compact plastic housing (5×8cm / 2.0×3.1in); powered by 3 AAA batteries (not included), suitable for flexible placement indoors or covered outdoor areas Versatile Usage Scenarios – Works in apartments, houses, factories, and commercial spaces; functions as a guest welcome system or perimeter alert with reliable wireless signal, Weight: 0.21825763938 pounds, Manufacturer: Zerodis