Discalo LED Wall or ceiling surface mounted luminaire. High transmission opal diffuser retained, with white surrounding trim. Die cast aluminium base with self-cooling ventilation optimises thermal performance. Backlight diffuser provides white halo lighting effect. Options: LE3 - Lithium Emergency (192 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) R25E - Reacta 25, On / Off High Frequency R25C - Reacta 25, Corridor Mode* R25W - Reacta-Wave Wireless sensor DALI R25WE - Reacta-Wave Wireless sensor On/Off *Bi-Level Dimming. Will only dim the luminaire to 10% during absence and brightout, it will not turn the luminaire off.