VESDA VLF-250 smoke detectors are early-warning detectors designed to protect small, business-critical environments of less than 250 m2 (2,690'2). The detectors work by continually drawing air into sampling holes in pipe networks. Air is filtered and passed into detection chambers where light scattering technology detects the presence of very small amounts of smoke. Status information appears on the detectors' display and via relays or optional interface cards.