Protec LED High Output - Ø174mm, IP20 Recessed High Output Downlighter with a 60 Degree Lens, ABS housing and bezel, zinc plated spring steel fixing clips and anodised semi specular aluminium reflector and opal diffuser. E3 - Emergency control gear (416 lumens output) - Attachments may reduce emergency lumen ouput. 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)* Replace * with WH for White or GY for Grey Order the luminaire with trim accessory attachment