Working Modes: LED light flashing only, or both sound and LED flashing. Volume Adjustment: 3 levels (high, medium, low). Ringtones: 38 built-in options. Effective receiver range: up to 70 meters. PIR motion detection range: 3–7 meters. Suitable for use in homes, offices, stores, hotels, and other buildings. Ideal for alerting business owners working in back areas or out of sight when customers enter. Can also be used as a signal for animal entry or exit. Applications: entrance alert, intruder alarm, passageway alarm, indoor car alarm, warehouse monitoring, power supply closet alarm, garage and tool shed monitoring, mailbox sensor, front door or walkway detection. Package includes: one plug-in electronic receiver, two PIR motion detectors (powered by 3 AAA batteries, not included), and English instructions.