Ring shaped luminaire housing from rolled aluminium extruded profile, seamlessly welded; surface powder coated; pendant fitting with cable suspension; with integrated tool-less suspension height adjustment; incl. transparent feed; light inset consisting of highly reflective coated die-cast aluminium for improved thermal management; HPO (High Performance Opal) cover for uniform illumination; micro prismatic PMMA diffuser incl. diffuser film for homogeneous illumination and reduced luminance; optional with direct/indirect illumination characteristic for additional emphasis of the ceiling and more visual comfort; energy-efficient LEDs with very good colour rendering; sound absorbing elements available