Round recessed luminaire in aluminium, consisting of (SONO) light housing and recessed housing; housing with trim suitable for installation in plasterboard ceilings; suitable for ceiling thickness of 10-25 mm; optionally: installation in concrete ceilings with a special installation housing (available as an accessory); surface powder coated; luminaire installs in housing without tools optionally flush or protruding by 25 mm; completely homogeneously illuminated, satinised PMMA cover; same luminance for all size versions; energy-efficient LEDs with very good colour rendering; luminaire with 2 cable openings and plug-in terminals for through wiring