Square aluminium luminaire housing with trim; suitable for installation in plasterboard ceilings; suitable for ceiling thickness of 10-25 mm; surface white powder coated; light inset consisting of converter unit and circuit board unit; installation without tools using snap spring closure; electrical connection by means of reverse polarity protected plug system; highly reflective coating for improved efficiency; completely homogeneously illuminated, satinised or microprismatic PMMA cover; workplace light suitable for VDUs according to DIN EN 12464-1 (UGR < 19); cover removable without tools for easy maintenance; same luminance for all flat luminaires; energy-efficient LEDs with very good colour rendering; binning initial ≤ 3 MacAdam; available in the light colours 3000K and 4000K; CRI ≥ 80; min. 90 % of the luminous flux after 50000 hours; external converter for ceiling insertion, through-wiring suitable; degree of protection IP 20; PC I; photobiological safety according to IEC 62471 risk group 0; DALI dimmable with CLO function; optional non-dimmable