Passage detector alarm, communication range up to 100m (distance between the infrared receivers and the receiver). The infrared receiver range is 3-7m. Notifies you in advance when guests (or intruders) arrive. Motion detector alarm with 38 ringtones, you can choose the ringtone(s) you want! 3 volume adjustment levels: high, medium or low. Receiver working mode: flashing LED light only or both sound and flashing LED. Power supply (receiver): AC 110-240V . Power supply (transmitter): 3 1.5V AAA batteries (not included) or 5V DC adapter (not included) Applications: driveway alarm, burglar alarm, walk-through alarm, creature detector, car security alarm (indoor), warehouse monitoring, electric cabinet alarm, garage and tool shed monitoring, mailbox sensor, front door or gateway detection.