AQUA Ring is a digital passive infrared detector in oval enclosure, designed for ceiling mounting. It is ideally suited for use in locations where wall mounting is difficult or just impossible, for example, in rooms with fully glazed walls or showcases. It can also be used in spacious premises because its design allows protection of a large area. AQUA Ring is provided with a quad element PIR sensor and digital motion detection algorithm. Owing to the two-track analysis of the signal from the PIR sensor (valuable and quantitative) and the temperature compensation feature, the device is characterized by high sensitivity and interference immunity. Three-step sensitivity control makes it possible to adjust the device performance to the requirements of the user and the protected premises. The detector has a tamper switch to protect it against opening the enclosure. The device meets the EN-50131 requirements for Grade 2.