Boasting a miniature size of 8.6cm (3-3/8 inches) and sleek elegant design, Disc blends inconspicuously into any déecor. Into this miniature unnoticeable housing, Visonic packs a powerful combination of features, for maximal performance, reliability and false alarm immunity. Standard features include: a high-quality, low-noise dual-element detector; 360o detection pattern; floor coverage of up to 10.8m (36ft), adjustable pulse counter, and more. The Disc miniature PIR detector is easily installed in any ceiling up to 3.6m (12 ft). Its elegant design, durable construction and simple installation make Disc the best professional choice of ceiling mount PIR detector for home, office and other commercial applications Disc Features: The world's smallest ceiling-mount PIR detector. Dimensions: 8.6cm (3.4 inch) diameter, 2.5cm (1 inch) depth. Blends seamlessly into any déecor. 360 deg. detection pattern. Floor coverage of up to 10.8m (36ft). Adjustable 1 or 2 alternate polarity pulse counter. Exceptionally high reliability and false alarm immunity. Easily installed in any ceiling up to 3.6m (12 ft). Durable sleek and elegant design.