2 working modes available for choice: only LED Light flashing or both sound and LED flashing. 3 levels of volume adjustment: High or Medium or Low. 38 ringtones for choose. Receiver working effective range is up to 70 meters. PIR motion detection distance is 3-7 meters. Ideal for alerting business owners who work behind the scenes or out of sight when customers enter the store. It can also be used as a signal when animal is ready to enter or leave. Applications: entry alert, intruder alarm, passageway alarm, bug detector, car alarm (indoor), security monitor warehouse, power supply closet alarm, garage and tool shed monitor, mailbox sensor, front door or walkway detection. Package includes: plug-in electronic receiver, motion detector PIR (power by 3 AAA batteries, NOT INCLUDED) and English instructions.