Arcus Mono - 1200x600, IP30 Recessed lay-in luminaire, steel gull wing housing white powder painted finish, extruded polycarbonate single diffuser. Suitable for lay in applications in 15mm and 24mm exposed T ceiling systems. Options: E3 - Emergency control gear (830 lumens output) ST3 - Emergency Selftest AT3 - Emergency Autotest S - Switch Dimming D - Digital Dimming (DSI) A - Digital Addressable Lighting Interface (DALI) C - Bi-Level Dimming (Corridor Function) H - High Frequency Dimming (Analogue 1-10v) R44 - Daylight regulating and Occupancy Sensor RLS - Reacta-Link Wireless Presence & Daylight Sensor RC - Reacta-Control Wireless Module