Round luminaire housing made of die-cast aluminium in 2 different diameters; with trim; suitable for ceiling thickness of 2-25 mm; surface white powder coated; installation without tools using snap spring closure; reflector made of polycarbonate, polished chrome; choice of symmetric or asymmetric radiation characteristic; lighting level recessed; also available as screen work capable luminaire as per DIN EN 12464-1 (UGR < 19); passive cooling of LEDs with optimised heat sink geometry; energy-efficient LEDs with very good colour rendering; binning initial ≤ 3 MacAdam; available in the light colours 3000K and 4000K, optionally with tunable-white diodes (3000-4000 K); CRI ≥ 80; min. 80 % of the luminous flux after 50000 hours; external converter for ceiling insertion, through-wiring suitable; degree of protection IP 44; PC II; operating device suitable for use with a central battery system; optional DALI dimmable