About this item RECEIVER has an ON/OFF switch and a VOLUME CONTROL. 16 alert sounds are selectable and each melody will play for a set duration, some repeat and sound off for 20s, some are as simple as doorbell rings and only last for a few seconds. Duration is dependent on the choice of the melody you desired. 5 volume levels up to 100 dB (MUTE included), along with the LED light indicator flashing, fantastic to give a visual alert that someone is coming up your door or the perimeter. PIR SENSOR picks up any movement 20ft in front of it, and send a signal up to 500ft (in open area) long range back to the receiver which chimes. The sensor is a passive infrared motion sensor that detects heat movement, 90 degree viewing radius from dead center, can be adjusted by 2 window covers in the kit. With the durable plastic lens and weather resistant casing (waterproof IPV4), it is suitable for monitoring proximity outdoor areas such as driveway, front door, porch, shed, garage, etc. HOLDS UP TO 8 SENSORS with 2 assigned to 4 zones, and any time a sensor that's triggered activates the zone it's paired with lights up (RED-1,GREEN-2,BLUE-3,PURPLE-4). Choose a different ringtone for each sensor, so that when a sensor is set off, you can easily tell where the motion has taken place by the LED color or a specific ringtone. ie Set your entrance of your store to zone 1, and set backdoor to zone 2, if motion is detected at the back, the GREEN LED lights and sound goes off. WIRELESS PIR runs on 2* AA batteries (Not Included) for up to one year, portable receiver can be either plugged in using included AC adaptor or can run on 3* AA batteries (Not Included). Plugging in any standard outlet and using the batteries as a backup, even if there are no batteries in the receiver, it will retain the paring and alarm tone choices if unplugged or power fails. 1 sensor and 1 receiver are already pre-programmed so it is ready to work right out of the box. THE RECOMMEND POSITION is mounting the sensor 3-4ft above the ground at the entrance to your driveway and pointed straight out towards your house. The mounting plate has 2 screw holes for mounting, screwed it right to the fence post, tree, stake in ground and more. This will decrease or eliminate false alarms from small animals, and avoid unwanted alarms from nearby traffic. You can minimize the effect by selecting the detecting range and adjust the aiming angle to cover the desired area.