AQUA S is a digital passive infrared detector equipped with a dual element PIR sensor. Owing to the use of digital motion detection algorithm it is characterized by good immunity to interference and false alarms. Interchangeable Fresnel lens and three-step sensitivity control make it possible to adjust the device performance to requirements of the user and the protected premises. The detector has a built-in pre-alarm feature and tamper switch to protect it against opening the enclosure. Because the detector can be powered from a 24 V DC or AC source, it is intended for systems running on 24 V (instead of the standard 12 V) voltage.