The unbranded Black High-Back Ergonomic Office Chair, model EOCH-DB670-BLK, presents a streamlined, professional silhouette finished in matte black across all components, designed to balance understated office aesthetics and targeted postural support. Its structured layout pairs a 700mm tall dual split backrest with a contoured fixed lumbar pad, an adjustable padded headrest, and integrated curved loop armrests, all mounted to a central swivel joint connected to a five-star base fitted with smooth rolling casters. The seat cushion measures 510mm wide and 500mm deep, paired with an 80mm thick high-density foam core set on a 12mm plywood base, while backrest panels carry 50mm thick padding for consistent pressure distribution. All fabric surfaces use 0.8mm thick black woven polyester upholstery, stitched with durable polyester thread at an 8mm stitch pitch. Structural components include a glass-fiber reinforced nylon back frame, 3mm wall thickness matte nylon five-star base, chrome-plated Class 4 steel gas lift, 2.5mm steel plate tilt mechanism, and non-marking nylon dual-wheel casters engineered for 100,000 rolling cycles. The chair supports full 360-degree horizontal swivel, 100mm pneumatic seat height adjustment set to a maximum 530mm seat height, 3-position lockable backrest recline with adjustable tension, height-adjustable headrest for cervical support, and independent split back panels that flex to match natural spinal movement. The fixed integrated armrests deliver stable forearm support aligned to standard desk heights, and the 50 kg/m³ seat foam with 45% rebound rate delivers resilient cushioning for extended seated sessions. It is rated to support a maximum user weight of 181kg, with a net weight of 18kg. This chair is suited for a range of work and study settings, including corporate open office workstations, home office workspaces, private manager offices, coworking spaces, meeting and conference rooms, and home study or computer desks, where it delivers reliable support for 8+ hours of daily desk-based work, meetings, remote work, or study. For procurement, note that each unit ships in 2 cartons with a total packaged gross weight of 23kg and 0.26 m³ total carton volume, requires 40 minutes of assembly per set, and fits 135 units per 20GP container at 85% space utilization. The fixed armrest and fixed lumbar support design should be evaluated against user needs for adjustable arm positioning before bulk purchase, and its consistent black finish coordinates with most standard office interior palettes.