Halobay Surface Surface mounted luminaire, spun aluminium housing, high transmission opal polycarbonate dished diffuser. Options: LE3 - Lithium Emergency (593 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) RLS - Reacta-Link Wireless Presence