Dual - 600x600, IP20 Recessed lay-in luminaire, white powder coated steel body, twin high transmission opal diffusers, suitable for lay in installation in exposed "T" ceiling systems. Options: LE3 - Lithium Emergency (418 lumens output) LS3 - Lithium Selftest LA3 - Lithium 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 - Reacta 44, Daylight and Presence Detection Sensor RAS - Reacta Air Wireless Presence & daylight RLI - Reacta-Link Wireless Module RLS - Reacta-Link Wireless Presence & Daylight Sensor RC - Reacta-Control Wireless Module RCS - Reacta-Control Wireless, Presence