2 working modes available: LED light flashing only, or both sound and LED flashing. 3 volume levels: High, Medium, or Low. 38 ringtones to choose from. Receiver effective working range up to 70 meters. PIR motion detection distance is 3-7 meters. Suitable for use in homes, offices, stores, hotels, and other buildings. Ideal for alerting business owners when customers enter the store, especially when working in the back or out of sight. Can also be used as a signal when animals enter or leave an area. Applications include: entry alert, intruder alarm, passageway alarm, bug detector, indoor car alarm, security monitoring, warehouse alarm, 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.